51661400 has 48 divisors (see below), whose sum is σ = 137275440. Its totient is φ = 17712000.

The previous prime is 51661397. The next prime is 51661411. The reversal of 51661400 is 416615.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 17051 + ... + 19850.

It is an arithmetic number, because the mean of its divisors is an integer number (2859905).

Almost surely, 2^51661400 is an apocalyptic number.

51661400 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

It is an amenable number.

51661400 is an abundant number, since it is smaller than the sum of its proper divisors (85614040).

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

51661400 is a wasteful number, since it uses less digits than its factorization.

51661400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36924 (or 36915 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 51661400 is about 7187.5865212184. The cubic root of 51661400 is about 372.4392045280.

It can be divided in two parts, 516 and 61400, that added together give a palindrome (61916).

The spelling of 51661400 in words is "fifty-one million, six hundred sixty-one thousand, four hundred".