25513455021 has 16 divisors (see below), whose sum is σ = 34582310400. Its totient is φ = 16726893120.

The previous prime is 25513455013. The next prime is 25513455053. The reversal of 25513455021 is 12055431552.

It is not a de Polignac number, because 25513455021 - 2³ = 25513455013 is a prime.

It is a super-2 number, since 2×25513455021² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25513455091) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1261636 + ... + 1281698.

It is an arithmetic number, because the mean of its divisors is an integer number (2161394400).

Almost surely, 2^25513455021 is an apocalyptic number.

It is an amenable number.

25513455021 is a deficient number, since it is larger than the sum of its proper divisors (9068855379).

25513455021 is a wasteful number, since it uses less digits than its factorization.

25513455021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27076.

The product of its (nonzero) digits is 30000, while the sum is 33.

Adding to 25513455021 its reverse (12055431552), we get a palindrome (37568886573).

The spelling of 25513455021 in words is "twenty-five billion, five hundred thirteen million, four hundred fifty-five thousand, twenty-one".