51515399 has 8 divisors (see below), whose sum is σ = 56260512. Its totient is φ = 46882080.

The previous prime is 51515371. The next prime is 51515407. The reversal of 51515399 is 99351515.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51515399 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 (51515369) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26984 + ... + 28829.

It is an arithmetic number, because the mean of its divisors is an integer number (7032564).

Almost surely, 2^51515399 is an apocalyptic number.

51515399 is a deficient number, since it is larger than the sum of its proper divisors (4745113).

51515399 is a wasteful number, since it uses less digits than its factorization.

51515399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55897.

The product of its digits is 30375, while the sum is 38.

The square root of 51515399 is about 7177.4228661825. The cubic root of 51515399 is about 372.0880216228.

The spelling of 51515399 in words is "fifty-one million, five hundred fifteen thousand, three hundred ninety-nine".