51409904 has 160 divisors (see below), whose sum is σ = 135991296. Its totient is φ = 18247680.

The previous prime is 51409889. The next prime is 51409907. The reversal of 51409904 is 40990415.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51409907) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 767279 + ... + 767345.

Almost surely, 2^51409904 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 51409904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (67995648).

51409904 is an abundant number, since it is smaller than the sum of its proper divisors (84581392).

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

51409904 is a wasteful number, since it uses less digits than its factorization.

51409904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143 (or 137 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 32.

The square root of 51409904 is about 7170.0700136052. The cubic root of 51409904 is about 371.8338565126.

The spelling of 51409904 in words is "fifty-one million, four hundred nine thousand, nine hundred four".