51151997 has 16 divisors (see below), whose sum is σ = 59330880. Its totient is φ = 43675392.

The previous prime is 51151981. The next prime is 51151999. The reversal of 51151997 is 79915115.

It is a cyclic number.

It is not a de Polignac number, because 51151997 - 2⁴ = 51151981 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 51151997.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51151999) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11078 + ... + 15000.

It is an arithmetic number, because the mean of its divisors is an integer number (3708180).

Almost surely, 2^51151997 is an apocalyptic number.

It is an amenable number.

51151997 is a deficient number, since it is larger than the sum of its proper divisors (8178883).

51151997 is a wasteful number, since it uses less digits than its factorization.

51151997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4012.

The product of its digits is 14175, while the sum is 38.

The square root of 51151997 is about 7152.0624298170. The cubic root of 51151997 is about 371.2110234299.

The spelling of 51151997 in words is "fifty-one million, one hundred fifty-one thousand, nine hundred ninety-seven".