51156993 has 4 divisors (see below), whose sum is σ = 68209328. Its totient is φ = 34104660.

The previous prime is 51156983. The next prime is 51157019. The reversal of 51156993 is 39965115.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 51156993 - 2⁸ = 51156737 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51156923) 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, 8526163 + ... + 8526168.

It is an arithmetic number, because the mean of its divisors is an integer number (17052332).

Almost surely, 2^51156993 is an apocalyptic number.

It is an amenable number.

51156993 is a deficient number, since it is larger than the sum of its proper divisors (17052335).

51156993 is a wasteful number, since it uses less digits than its factorization.

51156993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17052334.

The product of its digits is 36450, while the sum is 39.

The square root of 51156993 is about 7152.4116911710. The cubic root of 51156993 is about 371.2231083924.

The spelling of 51156993 in words is "fifty-one million, one hundred fifty-six thousand, nine hundred ninety-three".