51515999 has 2 divisors, whose sum is σ = 51516000. Its totient is φ = 51515998.

The previous prime is 51515983. The next prime is 51516013. The reversal of 51515999 is 99951515.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 51515999 - 2⁴ = 51515983 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51575999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25757999 + 25758000.

It is an arithmetic number, because the mean of its divisors is an integer number (25758000).

Almost surely, 2^51515999 is an apocalyptic number.

51515999 is a deficient number, since it is larger than the sum of its proper divisors (1).

51515999 is an equidigital number, since it uses as much as digits as its factorization.

51515999 is an evil number, because the sum of its binary digits is even.

The product of its digits is 91125, while the sum is 44.

The square root of 51515999 is about 7177.4646637932. The cubic root of 51515999 is about 372.0894661873.

The spelling of 51515999 in words is "fifty-one million, five hundred fifteen thousand, nine hundred ninety-nine".