51515539 has 2 divisors, whose sum is σ = 51515540. Its totient is φ = 51515538.

The previous prime is 51515533. The next prime is 51515549. The reversal of 51515539 is 93551515.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 51515539 - 2²⁵ = 17961107 is a prime.

It is not a weakly prime, because it can be changed into another prime (51515533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25757769 + 25757770.

It is an arithmetic number, because the mean of its divisors is an integer number (25757770).

Almost surely, 2^51515539 is an apocalyptic number.

51515539 is a deficient number, since it is larger than the sum of its proper divisors (1).

51515539 is an equidigital number, since it uses as much as digits as its factorization.

51515539 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 16875, while the sum is 34.

The square root of 51515539 is about 7177.4326189801. The cubic root of 51515539 is about 372.0883586889.

The spelling of 51515539 in words is "fifty-one million, five hundred fifteen thousand, five hundred thirty-nine".