51216504 has 16 divisors (see below), whose sum is σ = 128041320. Its totient is φ = 17072160.

The previous prime is 51216493. The next prime is 51216509. The reversal of 51216504 is 40561215.

It is a Harshad number since it is a multiple of its sum of digits (24), and also a Moran number because the ratio is a prime number: 2134021 = 51216504 / (5 + 1 + 2 + 1 + 6 + 5 + 0 + 4).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51216509) 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, 1066987 + ... + 1067034.

Almost surely, 2^51216504 is an apocalyptic number.

It is an amenable number.

51216504 is an abundant number, since it is smaller than the sum of its proper divisors (76824816).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51216504 is a wasteful number, since it uses less digits than its factorization.

51216504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2134030 (or 2134026 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 24.

The square root of 51216504 is about 7156.5706871378. The cubic root of 51216504 is about 371.3670007268.

Adding to 51216504 its reverse (40561215), we get a palindrome (91777719).

The spelling of 51216504 in words is "fifty-one million, two hundred sixteen thousand, five hundred four".