51991042 has 8 divisors (see below), whose sum is σ = 79800336. Its totient is φ = 25390932.

The previous prime is 51991007. The next prime is 51991081. The reversal of 51991042 is 24019915.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 51990995 and 51991013.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 302188 + ... + 302359.

It is an arithmetic number, because the mean of its divisors is an integer number (9975042).

Almost surely, 2^51991042 is an apocalyptic number.

51991042 is a deficient number, since it is larger than the sum of its proper divisors (27809294).

51991042 is a wasteful number, since it uses less digits than its factorization.

51991042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 604592.

The product of its (nonzero) digits is 3240, while the sum is 31.

The square root of 51991042 is about 7210.4813986307. The cubic root of 51991042 is about 373.2296812233.

It can be divided in two parts, 5199 and 1042, that added together give a square (6241 = 79²).

The spelling of 51991042 in words is "fifty-one million, nine hundred ninety-one thousand, forty-two".