51397778 has 16 divisors (see below), whose sum is σ = 81285120. Its totient is φ = 24326016.

The previous prime is 51397769. The next prime is 51397811. The reversal of 51397778 is 87779315.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1298 + ... + 10221.

It is an arithmetic number, because the mean of its divisors is an integer number (5080320).

Almost surely, 2^51397778 is an apocalyptic number.

51397778 is a deficient number, since it is larger than the sum of its proper divisors (29887342).

51397778 is a wasteful number, since it uses less digits than its factorization.

51397778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11641.

The product of its digits is 370440, while the sum is 47.

The square root of 51397778 is about 7169.2243652992. The cubic root of 51397778 is about 371.8046195268.

The spelling of 51397778 in words is "fifty-one million, three hundred ninety-seven thousand, seven hundred seventy-eight".