51615500 has 24 divisors (see below), whose sum is σ = 112729344. Its totient is φ = 20646000.

The previous prime is 51615493. The next prime is 51615503. The reversal of 51615500 is 551615.

It is not an unprimeable number, because it can be changed into a prime (51615503) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 51116 + ... + 52115.

It is an arithmetic number, because the mean of its divisors is an integer number (4697056).

Almost surely, 2^51615500 is an apocalyptic number.

51615500 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

It is an amenable number.

51615500 is an abundant number, since it is smaller than the sum of its proper divisors (61113844).

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

51615500 is a wasteful number, since it uses less digits than its factorization.

51615500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103250 (or 103238 counting only the distinct ones).

The product of its (nonzero) digits is 750, while the sum is 23.

The square root of 51615500 is about 7184.3928066330. The cubic root of 51615500 is about 372.3288705402.

It can be divided in two parts, 516 and 15500, that multiplied together give a triangular number (7998000 = T₃₉₉₉).

The spelling of 51615500 in words is "fifty-one million, six hundred fifteen thousand, five hundred".