21812115240 has 128 divisors (see below), whose sum is σ = 73238256000. Its totient is φ = 5774068224.

The previous prime is 21812115239. The next prime is 21812115263. The reversal of 21812115240 is 4251121812.

21812115240 is a `hidden beast` number, since 2 + 18 + 121 + 1 + 524 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 74251 + ... + 221669.

It is an arithmetic number, because the mean of its divisors is an integer number (572173875).

Almost surely, 2^21812115240 is an apocalyptic number.

21812115240 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 21812115240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36619128000).

21812115240 is an abundant number, since it is smaller than the sum of its proper divisors (51426140760).

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

21812115240 is a wasteful number, since it uses less digits than its factorization.

21812115240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147576 (or 147566 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 27.

The spelling of 21812115240 in words is "twenty-one billion, eight hundred twelve million, one hundred fifteen thousand, two hundred forty".