51115980 has 72 divisors (see below), whose sum is σ = 148376592. Its totient is φ = 13147904.

The previous prime is 51115979. The next prime is 51116011. The reversal of 51115980 is 8951115.

It is a super-2 number, since 2×51115980² = 5225686822720800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 49954 + ... + 50966.

It is an arithmetic number, because the mean of its divisors is an integer number (2060786).

Almost surely, 2^51115980 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 51115980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (74188296).

51115980 is an abundant number, since it is smaller than the sum of its proper divisors (97260612).

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

51115980 is a wasteful number, since it uses less digits than its factorization.

51115980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1083 (or 1052 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 30.

The square root of 51115980 is about 7149.5440414057. The cubic root of 51115980 is about 371.1238776197.

The spelling of 51115980 in words is "fifty-one million, one hundred fifteen thousand, nine hundred eighty".