21165521050432 has 112 divisors (see below), whose sum is σ = 48341960801280. Its totient is φ = 9093189772800.

The previous prime is 21165521050351. The next prime is 21165521050441. The reversal of 21165521050432 is 23405012556112.

It is a super-2 number, since 2×21165521050432² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21165521050391 and 21165521050400.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3929383 + ... + 7600729.

Almost surely, 2^{21165521050432} is an apocalyptic number.

21165521050432 is a gapful number since it is divisible by the number (22) 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 21165521050432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24170980400640).

21165521050432 is an abundant number, since it is smaller than the sum of its proper divisors (27176439750848).

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

21165521050432 is a wasteful number, since it uses less digits than its factorization.

21165521050432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3671820 (or 3671810 counting only the distinct ones).

The product of its (nonzero) digits is 72000, while the sum is 37.

The spelling of 21165521050432 in words is "twenty-one trillion, one hundred sixty-five billion, five hundred twenty-one million, fifty thousand, four hundred thirty-two".