21152402525 has 12 divisors (see below), whose sum is σ = 27369370272. Its totient is φ = 16186185840.

The previous prime is 21152402521. The next prime is 21152402527. The reversal of 21152402525 is 52520425112.

It is a happy number.

It is not a de Polignac number, because 21152402525 - 2² = 21152402521 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21152402521) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18392819 + ... + 18393968.

It is an arithmetic number, because the mean of its divisors is an integer number (2280780856).

Almost surely, 2^21152402525 is an apocalyptic number.

21152402525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21152402525 is a deficient number, since it is larger than the sum of its proper divisors (6216967747).

21152402525 is a wasteful number, since it uses less digits than its factorization.

21152402525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36786820 (or 36786815 counting only the distinct ones).

The product of its (nonzero) digits is 8000, while the sum is 29.

Adding to 21152402525 its reverse (52520425112), we get a palindrome (73672827637).

The spelling of 21152402525 in words is "twenty-one billion, one hundred fifty-two million, four hundred two thousand, five hundred twenty-five".