21601020525 has 48 divisors (see below), whose sum is σ = 41585802624. Its totient is φ = 9688423680.

The previous prime is 21601020499. The next prime is 21601020541. The reversal of 21601020525 is 52502010612.

It is a happy number.

It is not a de Polignac number, because 21601020525 - 2¹² = 21601016429 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21601020495 and 21601020504.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 360334 + ... + 415983.

It is an arithmetic number, because the mean of its divisors is an integer number (866370888).

Almost surely, 2^21601020525 is an apocalyptic number.

21601020525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21601020525 is a deficient number, since it is larger than the sum of its proper divisors (19984782099).

21601020525 is a wasteful number, since it uses less digits than its factorization.

21601020525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 776390 (or 776385 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 24.

The spelling of 21601020525 in words is "twenty-one billion, six hundred one million, twenty thousand, five hundred twenty-five".