51505215 has 16 divisors (see below), whose sum is σ = 82531968. Its totient is φ = 27428256.

The previous prime is 51505213. The next prime is 51505273. The reversal of 51505215 is 51250515.

It is not a de Polignac number, because 51505215 - 2¹ = 51505213 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51505213) 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, 9624 + ... + 13986.

It is an arithmetic number, because the mean of its divisors is an integer number (5158248).

Almost surely, 2^51505215 is an apocalyptic number.

51505215 is a deficient number, since it is larger than the sum of its proper divisors (31026753).

51505215 is a wasteful number, since it uses less digits than its factorization.

51505215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5158.

The product of its (nonzero) digits is 1250, while the sum is 24.

The square root of 51505215 is about 7176.7133842728. The cubic root of 51505215 is about 372.0635008374.

The spelling of 51505215 in words is "fifty-one million, five hundred five thousand, two hundred fifteen".