64697989 has 2 divisors, whose sum is σ = 64697990. Its totient is φ = 64697988.

The previous prime is 64697987. The next prime is 64697993. The reversal of 64697989 is 98979646.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 59213025 + 5484964 = 7695^2 + 2342^2 .

It is a cyclic number.

It is not a de Polignac number, because 64697989 - 2¹ = 64697987 is a prime.

Together with 64697987, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64697981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32348994 + 32348995.

It is an arithmetic number, because the mean of its divisors is an integer number (32348995).

Almost surely, 2^64697989 is an apocalyptic number.

It is an amenable number.

64697989 is a deficient number, since it is larger than the sum of its proper divisors (1).

64697989 is an equidigital number, since it uses as much as digits as its factorization.

64697989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5878656, while the sum is 58.

The square root of 64697989 is about 8043.5060141707. The cubic root of 64697989 is about 401.4488892134.

The spelling of 64697989 in words is "sixty-four million, six hundred ninety-seven thousand, nine hundred eighty-nine".