51981902458 has 4 divisors (see below), whose sum is σ = 77972853690. Its totient is φ = 25990951228.

The previous prime is 51981902449. The next prime is 51981902477. The reversal of 51981902458 is 85420918915.

It is a happy number.

51981902458 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 43049195289 + 8932707169 = 207483^2 + 94513^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12995475613 + ... + 12995475616.

Almost surely, 2^51981902458 is an apocalyptic number.

51981902458 is a deficient number, since it is larger than the sum of its proper divisors (25990951232).

51981902458 is a wasteful number, since it uses less digits than its factorization.

51981902458 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25990951231.

The product of its (nonzero) digits is 1036800, while the sum is 52.

The spelling of 51981902458 in words is "fifty-one billion, nine hundred eighty-one million, nine hundred two thousand, four hundred fifty-eight".