51978651 has 4 divisors (see below), whose sum is σ = 69304872. Its totient is φ = 34652432.

The previous prime is 51978629. The next prime is 51978653. The reversal of 51978651 is 15687915.

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

It is a cyclic number.

It is not a de Polignac number, because 51978651 - 2⁷ = 51978523 is a prime.

It is not an unprimeable number, because it can be changed into a prime (51978653) 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, 8663106 + ... + 8663111.

It is an arithmetic number, because the mean of its divisors is an integer number (17326218).

Almost surely, 2^51978651 is an apocalyptic number.

51978651 is a deficient number, since it is larger than the sum of its proper divisors (17326221).

51978651 is a wasteful number, since it uses less digits than its factorization.

51978651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17326220.

The product of its digits is 75600, while the sum is 42.

The square root of 51978651 is about 7209.6221121498. The cubic root of 51978651 is about 373.2000283174.

The spelling of 51978651 in words is "fifty-one million, nine hundred seventy-eight thousand, six hundred fifty-one".