51439604402 has 4 divisors (see below), whose sum is σ = 77159406606. Its totient is φ = 25719802200.

The previous prime is 51439604401. The next prime is 51439604417. The reversal of 51439604402 is 20440693415.

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., 47785522801 + 3654081601 = 218599^2 + 60449^2 .

It is not an unprimeable number, because it can be changed into a prime (51439604401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12859901099 + ... + 12859901102.

Almost surely, 2^51439604402 is an apocalyptic number.

51439604402 is a deficient number, since it is larger than the sum of its proper divisors (25719802204).

51439604402 is a wasteful number, since it uses less digits than its factorization.

51439604402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25719802203.

The product of its (nonzero) digits is 103680, while the sum is 38.

The spelling of 51439604402 in words is "fifty-one billion, four hundred thirty-nine million, six hundred four thousand, four hundred two".