51392639 has 4 divisors (see below), whose sum is σ = 52646160. Its totient is φ = 50139120.

The previous prime is 51392629. The next prime is 51392659. The reversal of 51392639 is 93629315.

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

It is a cyclic number.

It is not a de Polignac number, because 51392639 - 2¹² = 51388543 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51392629) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 626699 + ... + 626780.

It is an arithmetic number, because the mean of its divisors is an integer number (13161540).

Almost surely, 2^51392639 is an apocalyptic number.

51392639 is a deficient number, since it is larger than the sum of its proper divisors (1253521).

51392639 is a wasteful number, since it uses less digits than its factorization.

51392639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1253520.

The product of its digits is 43740, while the sum is 38.

The square root of 51392639 is about 7168.8659493674. The cubic root of 51392639 is about 371.7922275020.

The spelling of 51392639 in words is "fifty-one million, three hundred ninety-two thousand, six hundred thirty-nine".