51551951 has 4 divisors (see below), whose sum is σ = 56238504. Its totient is φ = 46865400.

The previous prime is 51551933. The next prime is 51551953. The reversal of 51551951 is 15915515.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51551951 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51551953) 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, 2343260 + ... + 2343281.

It is an arithmetic number, because the mean of its divisors is an integer number (14059626).

Almost surely, 2^51551951 is an apocalyptic number.

51551951 is a deficient number, since it is larger than the sum of its proper divisors (4686553).

51551951 is a wasteful number, since it uses less digits than its factorization.

51551951 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4686552.

The product of its digits is 5625, while the sum is 32.

The square root of 51551951 is about 7179.9687325224. The cubic root of 51551951 is about 372.1760040268.

The spelling of 51551951 in words is "fifty-one million, five hundred fifty-one thousand, nine hundred fifty-one".