21145510622525 has 48 divisors (see below), whose sum is σ = 27325317817728. Its totient is φ = 16219362432000.

The previous prime is 21145510622479. The next prime is 21145510622531. The reversal of 21145510622525 is 52522601554112.

It is not a de Polignac number, because 21145510622525 - 2²⁰ = 21145509573949 is a prime.

It is a super-2 number, since 2×21145510622525² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 22314422 + ... + 23242728.

It is an arithmetic number, because the mean of its divisors is an integer number (569277454536).

Almost surely, 2^{21145510622525} is an apocalyptic number.

21145510622525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21145510622525 is a deficient number, since it is larger than the sum of its proper divisors (6179807195203).

21145510622525 is a wasteful number, since it uses less digits than its factorization.

21145510622525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 928742 (or 928737 counting only the distinct ones).

The product of its (nonzero) digits is 240000, while the sum is 41.

The spelling of 21145510622525 in words is "twenty-one trillion, one hundred forty-five billion, five hundred ten million, six hundred twenty-two thousand, five hundred twenty-five".