51723815 has 16 divisors (see below), whose sum is σ = 72920736. Its totient is φ = 34723200.

The previous prime is 51723811. The next prime is 51723823. The reversal of 51723815 is 51832715.

It is not a de Polignac number, because 51723815 - 2² = 51723811 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 (51723811) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 35456 + ... + 36885.

It is an arithmetic number, because the mean of its divisors is an integer number (4557546).

Almost surely, 2^51723815 is an apocalyptic number.

51723815 is a gapful number since it is divisible by the number (55) formed by its first and last digit.

51723815 is a deficient number, since it is larger than the sum of its proper divisors (21196921).

51723815 is a wasteful number, since it uses less digits than its factorization.

51723815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72370.

The product of its digits is 8400, while the sum is 32.

The square root of 51723815 is about 7191.9270713766. The cubic root of 51723815 is about 372.5891323123.

Subtracting 51723815 from its reverse (51832715), we obtain a square (108900 = 330²).

The spelling of 51723815 in words is "fifty-one million, seven hundred twenty-three thousand, eight hundred fifteen".