25489217978 has 48 divisors (see below), whose sum is σ = 45989051904. Its totient is φ = 10553548320.

The previous prime is 25489217959. The next prime is 25489217981. The reversal of 25489217978 is 87971298452.

It is a Harshad number since it is a multiple of its sum of digits (62).

It is a self number, because there is not a number n which added to its sum of digits gives 25489217978.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1855451 + ... + 1869137.

It is an arithmetic number, because the mean of its divisors is an integer number (958105248).

Almost surely, 2^25489217978 is an apocalyptic number.

25489217978 is a deficient number, since it is larger than the sum of its proper divisors (20499833926).

25489217978 is a wasteful number, since it uses less digits than its factorization.

25489217978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14347 (or 14340 counting only the distinct ones).

The product of its digits is 20321280, while the sum is 62.

The spelling of 25489217978 in words is "twenty-five billion, four hundred eighty-nine million, two hundred seventeen thousand, nine hundred seventy-eight".