645455022120 has 160 divisors (see below), whose sum is σ = 2171912577120. Its totient is φ = 171925649280.

The previous prime is 645455022103. The next prime is 645455022167. The reversal of 645455022120 is 21220554546.

645455022120 is a `hidden beast` number, since 64 + 5 + 4 + 550 + 2 + 21 + 20 = 666.

It is a super-2 number, since 2×645455022120² (a number of 24 digits) contains 22 as substring.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 2748115 + ... + 2973725.

It is an arithmetic number, because the mean of its divisors is an integer number (13574453607).

Almost surely, 2^645455022120 is an apocalyptic number.

645455022120 is a gapful number since it is divisible by the number (60) 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 645455022120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1085956288560).

645455022120 is an abundant number, since it is smaller than the sum of its proper divisors (1526457555000).

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

645455022120 is a wasteful number, since it uses less digits than its factorization.

645455022120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 226517 (or 226504 counting only the distinct ones).

The product of its (nonzero) digits is 96000, while the sum is 36.

Adding to 645455022120 its reverse (21220554546), we get a palindrome (666675576666).

The spelling of 645455022120 in words is "six hundred forty-five billion, four hundred fifty-five million, twenty-two thousand, one hundred twenty".