51505615 has 24 divisors (see below), whose sum is σ = 73584720. Its totient is φ = 34489728.

The previous prime is 51505613. The next prime is 51505621. The reversal of 51505615 is 51650515.

It is not a de Polignac number, because 51505615 - 2¹ = 51505613 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51505613) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8091 + ... + 12979.

It is an arithmetic number, because the mean of its divisors is an integer number (3066030).

Almost surely, 2^51505615 is an apocalyptic number.

51505615 is a deficient number, since it is larger than the sum of its proper divisors (22079105).

51505615 is a wasteful number, since it uses less digits than its factorization.

51505615 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4951 (or 4944 counting only the distinct ones).

The product of its (nonzero) digits is 3750, while the sum is 28.

The square root of 51505615 is about 7176.7412521283. The cubic root of 51505615 is about 372.0644640085.

The spelling of 51505615 in words is "fifty-one million, five hundred five thousand, six hundred fifteen".