51515869 has 2 divisors, whose sum is σ = 51515870. Its totient is φ = 51515868.

The previous prime is 51515851. The next prime is 51515923. The reversal of 51515869 is 96851515.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 43731769 + 7784100 = 6613^2 + 2790^2 .

It is a cyclic number.

It is not a de Polignac number, because 51515869 - 2⁷ = 51515741 is a prime.

It is a super-2 number, since 2×51515869² = 5307769517650322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51515809) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25757934 + 25757935.

It is an arithmetic number, because the mean of its divisors is an integer number (25757935).

Almost surely, 2^51515869 is an apocalyptic number.

It is an amenable number.

51515869 is a deficient number, since it is larger than the sum of its proper divisors (1).

51515869 is an equidigital number, since it uses as much as digits as its factorization.

51515869 is an evil number, because the sum of its binary digits is even.

The product of its digits is 54000, while the sum is 40.

The square root of 51515869 is about 7177.4556076649. The cubic root of 51515869 is about 372.0891531993.

It can be divided in two parts, 515 and 15869, that added together give a 14-th power (16384 = 2¹⁴).

The spelling of 51515869 in words is "fifty-one million, five hundred fifteen thousand, eight hundred sixty-nine".