51801516 has 108 divisors (see below), whose sum is σ = 150189312. Its totient is φ = 14962176.

The previous prime is 51801509. The next prime is 51801523. The reversal of 51801516 is 61510815.

It is an interprime number because it is at equal distance from previous prime (51801509) and next prime (51801523).

It is a self number, because there is not a number n which added to its sum of digits gives 51801516.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 135061 + ... + 135443.

Almost surely, 2^51801516 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 51801516, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (75094656).

51801516 is an abundant number, since it is smaller than the sum of its proper divisors (98387796).

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

51801516 is a wasteful number, since it uses less digits than its factorization.

51801516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 440 (or 418 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 27.

The square root of 51801516 is about 7197.3270038258. The cubic root of 51801516 is about 372.7756103301.

The spelling of 51801516 in words is "fifty-one million, eight hundred one thousand, five hundred sixteen".