21559051525 has 48 divisors (see below), whose sum is σ = 30839026176. Its totient is φ = 14803200000.

The previous prime is 21559051487. The next prime is 21559051561. The reversal of 21559051525 is 52515095512.

21559051525 is nontrivially palindromic in base 2, base 4 and base 16.

It is not a de Polignac number, because 21559051525 - 2¹³ = 21559043333 is a prime.

21559051525 is an undulating number in base 16.

It is a zygodrome in base 4.

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, 318685 + ... + 380365.

It is an arithmetic number, because the mean of its divisors is an integer number (642479712).

Almost surely, 2^21559051525 is an apocalyptic number.

21559051525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21559051525 is a deficient number, since it is larger than the sum of its proper divisors (9279974651).

21559051525 is a wasteful number, since it uses less digits than its factorization.

21559051525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61774 (or 61769 counting only the distinct ones).

The product of its (nonzero) digits is 112500, while the sum is 40.

The spelling of 21559051525 in words is "twenty-one billion, five hundred fifty-nine million, fifty-one thousand, five hundred twenty-five".