51511660 has 48 divisors (see below), whose sum is σ = 114508800. Its totient is φ = 19410624.

The previous prime is 51511657. The next prime is 51511693. The reversal of 51511660 is 6611515.

51511660 = T₃₁₉ + T₃₂₀ + ... + T₆₉₈.

It is a super-2 number, since 2×51511660² = 5306902231911200, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 107301 + ... + 107779.

It is an arithmetic number, because the mean of its divisors is an integer number (2385600).

Almost surely, 2^51511660 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51511660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (57254400).

51511660 is an abundant number, since it is smaller than the sum of its proper divisors (62997140).

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

51511660 is a wasteful number, since it uses less digits than its factorization.

51511660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 790 (or 788 counting only the distinct ones).

The product of its (nonzero) digits is 900, while the sum is 25.

The square root of 51511660 is about 7177.1623919206. The cubic root of 51511660 is about 372.0790193258.

The spelling of 51511660 in words is "fifty-one million, five hundred eleven thousand, six hundred sixty".