51871997 has 4 divisors (see below), whose sum is σ = 52100736. Its totient is φ = 51643260.

The previous prime is 51871993. The next prime is 51871999. The reversal of 51871997 is 79917815.

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 51871997 - 2² = 51871993 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 (51871993) 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, 114029 + ... + 114482.

It is an arithmetic number, because the mean of its divisors is an integer number (13025184).

Almost surely, 2^51871997 is an apocalyptic number.

It is an amenable number.

51871997 is a deficient number, since it is larger than the sum of its proper divisors (228739).

51871997 is a wasteful number, since it uses less digits than its factorization.

51871997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 228738.

The product of its digits is 158760, while the sum is 47.

The square root of 51871997 is about 7202.2216711234. The cubic root of 51871997 is about 372.9445995341.

The spelling of 51871997 in words is "fifty-one million, eight hundred seventy-one thousand, nine hundred ninety-seven".