25128321465 has 64 divisors (see below), whose sum is σ = 47047311360. Its totient is φ = 11341658880.

The previous prime is 25128321461. The next prime is 25128321479. The reversal of 25128321465 is 56412382152.

It is not a de Polignac number, because 25128321465 - 2² = 25128321461 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (25128321461) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 5464 + ... + 224246.

It is an arithmetic number, because the mean of its divisors is an integer number (735114240).

Almost surely, 2^25128321465 is an apocalyptic number.

It is an amenable number.

25128321465 is a deficient number, since it is larger than the sum of its proper divisors (21918989895).

25128321465 is a wasteful number, since it uses less digits than its factorization.

25128321465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 218854.

The product of its digits is 115200, while the sum is 39.

The spelling of 25128321465 in words is "twenty-five billion, one hundred twenty-eight million, three hundred twenty-one thousand, four hundred sixty-five".