21534455502 has 128 divisors (see below), whose sum is σ = 58461419520. Its totient is φ = 5741556480.

The previous prime is 21534455491. The next prime is 21534455519. The reversal of 21534455502 is 20555443512.

21534455502 is a `hidden beast` number, since 2 + 153 + 4 + 455 + 50 + 2 = 666.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 326248 + ... + 386660.

It is an arithmetic number, because the mean of its divisors is an integer number (456729840).

Almost surely, 2^21534455502 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21534455502, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29230709760).

21534455502 is an abundant number, since it is smaller than the sum of its proper divisors (36926964018).

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

21534455502 is a wasteful number, since it uses less digits than its factorization.

21534455502 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60495 (or 60489 counting only the distinct ones).

The product of its (nonzero) digits is 120000, while the sum is 36.

The spelling of 21534455502 in words is "twenty-one billion, five hundred thirty-four million, four hundred fifty-five thousand, five hundred two".