21355252525 has 24 divisors (see below), whose sum is σ = 28634774400. Its totient is φ = 15737122560.

The previous prime is 21355252511. The next prime is 21355252531. The reversal of 21355252525 is 52525255312.

It is not a de Polignac number, because 21355252525 - 2¹⁹ = 21354728237 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 514575 + ... + 554524.

It is an arithmetic number, because the mean of its divisors is an integer number (1193115600).

Almost surely, 2^21355252525 is an apocalyptic number.

21355252525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21355252525 is a deficient number, since it is larger than the sum of its proper divisors (7279521875).

21355252525 is a wasteful number, since it uses less digits than its factorization.

21355252525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1069173 (or 1069168 counting only the distinct ones).

The product of its digits is 150000, while the sum is 37.

The spelling of 21355252525 in words is "twenty-one billion, three hundred fifty-five million, two hundred fifty-two thousand, five hundred twenty-five".