51857993 has 4 divisors (see below), whose sum is σ = 56572368. Its totient is φ = 47143620.

The previous prime is 51857987. The next prime is 51858013. The reversal of 51857993 is 39975815.

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 a cyclic number.

It is not a de Polignac number, because 51857993 - 2¹² = 51853897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51857983) 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, 2357171 + ... + 2357192.

It is an arithmetic number, because the mean of its divisors is an integer number (14143092).

Almost surely, 2^51857993 is an apocalyptic number.

It is an amenable number.

51857993 is a deficient number, since it is larger than the sum of its proper divisors (4714375).

51857993 is a wasteful number, since it uses less digits than its factorization.

51857993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4714374.

The product of its digits is 340200, while the sum is 47.

The square root of 51857993 is about 7201.2494054851. The cubic root of 51857993 is about 372.9110349485.

The spelling of 51857993 in words is "fifty-one million, eight hundred fifty-seven thousand, nine hundred ninety-three".