51215355 has 64 divisors (see below), whose sum is σ = 98380800. Its totient is φ = 25194240.

The previous prime is 51215347. The next prime is 51215357. The reversal of 51215355 is 55351215.

51215355 is a `hidden beast` number, since 5 + 121 + 535 + 5 = 666.

It is not a de Polignac number, because 51215355 - 2³ = 51215347 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (51215357) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 104922 + ... + 105408.

It is an arithmetic number, because the mean of its divisors is an integer number (1537200).

Almost surely, 2^51215355 is an apocalyptic number.

51215355 is a deficient number, since it is larger than the sum of its proper divisors (47165445).

51215355 is a wasteful number, since it uses less digits than its factorization.

51215355 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 561 (or 555 counting only the distinct ones).

The product of its digits is 3750, while the sum is 27.

The square root of 51215355 is about 7156.4904108089. The cubic root of 51215355 is about 371.3642236020.

The spelling of 51215355 in words is "fifty-one million, two hundred fifteen thousand, three hundred fifty-five".