51391216 has 20 divisors (see below), whose sum is σ = 99725512. Its totient is φ = 25655616.

The previous prime is 51391201. The next prime is 51391229. The reversal of 51391216 is 61219315.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9991 + ... + 14233.

Almost surely, 2^51391216 is an apocalyptic number.

It is an amenable number.

51391216 is a deficient number, since it is larger than the sum of its proper divisors (48334296).

51391216 is a wasteful number, since it uses less digits than its factorization.

51391216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5008 (or 5002 counting only the distinct ones).

The product of its digits is 1620, while the sum is 28.

The square root of 51391216 is about 7168.7667000677. The cubic root of 51391216 is about 371.7887959780.

The spelling of 51391216 in words is "fifty-one million, three hundred ninety-one thousand, two hundred sixteen".