51604642 has 4 divisors (see below), whose sum is σ = 77406966. Its totient is φ = 25802320.

The previous prime is 51604621. The next prime is 51604661. The reversal of 51604642 is 24640615.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 24640615 = 5 ⋅4928123.

It can be written as a sum of positive squares in only one way, i.e., 48288601 + 3316041 = 6949^2 + 1821^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 51604642.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12901159 + ... + 12901162.

Almost surely, 2^51604642 is an apocalyptic number.

51604642 is a deficient number, since it is larger than the sum of its proper divisors (25802324).

51604642 is a wasteful number, since it uses less digits than its factorization.

51604642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25802323.

The product of its (nonzero) digits is 5760, while the sum is 28.

The square root of 51604642 is about 7183.6371010791. The cubic root of 51604642 is about 372.3027606160.

The spelling of 51604642 in words is "fifty-one million, six hundred four thousand, six hundred forty-two".