51681404 has 12 divisors (see below), whose sum is σ = 91975800. Its totient is φ = 25402608.

The previous prime is 51681403. The next prime is 51681419. The reversal of 51681404 is 40418615.

It is a super-2 number, since 2×51681404² = 5341935038822432, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51681401) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 109259 + ... + 109730.

It is an arithmetic number, because the mean of its divisors is an integer number (7664650).

Almost surely, 2^51681404 is an apocalyptic number.

It is an amenable number.

51681404 is a deficient number, since it is larger than the sum of its proper divisors (40294396).

51681404 is a wasteful number, since it uses less digits than its factorization.

51681404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 219052 (or 219050 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 29.

The square root of 51681404 is about 7188.9779523935. The cubic root of 51681404 is about 372.4872695077.

The spelling of 51681404 in words is "fifty-one million, six hundred eighty-one thousand, four hundred four".