65815987 has 2 divisors, whose sum is σ = 65815988. Its totient is φ = 65815986.

The previous prime is 65815969. The next prime is 65815991. The reversal of 65815987 is 78951856.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 65815987 - 2¹¹ = 65813939 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 65815987.

It is not a weakly prime, because it can be changed into another prime (65815907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32907993 + 32907994.

It is an arithmetic number, because the mean of its divisors is an integer number (32907994).

Almost surely, 2^65815987 is an apocalyptic number.

65815987 is a deficient number, since it is larger than the sum of its proper divisors (1).

65815987 is an equidigital number, since it uses as much as digits as its factorization.

65815987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 604800, while the sum is 49.

The square root of 65815987 is about 8112.7052824566. The cubic root of 65815987 is about 403.7480763646.

The spelling of 65815987 in words is "sixty-five million, eight hundred fifteen thousand, nine hundred eighty-seven".