51506615 has 8 divisors (see below), whose sum is σ = 61978560. Its totient is φ = 41091552.

The previous prime is 51506569. The next prime is 51506621. The reversal of 51506615 is 51660515.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 51506615 - 2¹⁶ = 51441079 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12200 + ... + 15869.

It is an arithmetic number, because the mean of its divisors is an integer number (7747320).

Almost surely, 2^51506615 is an apocalyptic number.

51506615 is a deficient number, since it is larger than the sum of its proper divisors (10471945).

51506615 is a wasteful number, since it uses less digits than its factorization.

51506615 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28441.

The product of its (nonzero) digits is 4500, while the sum is 29.

The square root of 51506615 is about 7176.8109212937. The cubic root of 51506615 is about 372.0668719147.

The spelling of 51506615 in words is "fifty-one million, five hundred six thousand, six hundred fifteen".