25745157921 has 16 divisors (see below), whose sum is σ = 40187564928. Its totient is φ = 14352700800.

The previous prime is 25745157917. The next prime is 25745157953. The reversal of 25745157921 is 12975154752.

It is a happy number.

It is not a de Polignac number, because 25745157921 - 2² = 25745157917 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (25745157961) 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, 14949870 + ... + 14951591.

It is an arithmetic number, because the mean of its divisors is an integer number (2511722808).

Almost surely, 2^25745157921 is an apocalyptic number.

25745157921 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

25745157921 is a deficient number, since it is larger than the sum of its proper divisors (14442407007).

25745157921 is a wasteful number, since it uses less digits than its factorization.

25745157921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29901512.

The product of its digits is 882000, while the sum is 48.

The spelling of 25745157921 in words is "twenty-five billion, seven hundred forty-five million, one hundred fifty-seven thousand, nine hundred twenty-one".