212155425540 has 144 divisors (see below), whose sum is σ = 661459518720. Its totient is φ = 55001721600.

The previous prime is 212155425527. The next prime is 212155425553. The reversal of 212155425540 is 45524551212.

212155425540 is a `hidden beast` number, since 2 + 1 + 21 + 5 + 542 + 55 + 40 = 666.

It is an interprime number because it is at equal distance from previous prime (212155425527) and next prime (212155425553).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 212155425495 and 212155425504.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 8772465 + ... + 8796615.

It is an arithmetic number, because the mean of its divisors is an integer number (4593468880).

Almost surely, 2^212155425540 is an apocalyptic number.

212155425540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 212155425540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (330729759360).

212155425540 is an abundant number, since it is smaller than the sum of its proper divisors (449304093180).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

212155425540 is a wasteful number, since it uses less digits than its factorization.

212155425540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25522 (or 25517 counting only the distinct ones).

The product of its (nonzero) digits is 80000, while the sum is 36.

Adding to 212155425540 its reverse (45524551212), we get a palindrome (257679976752).

The spelling of 212155425540 in words is "two hundred twelve billion, one hundred fifty-five million, four hundred twenty-five thousand, five hundred forty".