64997491 has 8 divisors (see below), whose sum is σ = 70366464. Its totient is φ = 59681280.

The previous prime is 64997489. The next prime is 64997507. The reversal of 64997491 is 19479946.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 64997491 - 2¹ = 64997489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64997441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10606 + ... + 15571.

It is an arithmetic number, because the mean of its divisors is an integer number (8795808).

Almost surely, 2^64997491 is an apocalyptic number.

64997491 is a deficient number, since it is larger than the sum of its proper divisors (5368973).

64997491 is a wasteful number, since it uses less digits than its factorization.

64997491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26381.

The product of its digits is 489888, while the sum is 49.

The square root of 64997491 is about 8062.1021452224. The cubic root of 64997491 is about 402.0674024585.

The spelling of 64997491 in words is "sixty-four million, nine hundred ninety-seven thousand, four hundred ninety-one".