64248991 has 4 divisors (see below), whose sum is σ = 64296000. Its totient is φ = 64201984.

The previous prime is 64248931. The next prime is 64249021. The reversal of 64248991 is 19984246.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 64248991 - 2²³ = 55860383 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64248901) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21391 + ... + 24208.

It is an arithmetic number, because the mean of its divisors is an integer number (16074000).

Almost surely, 2^64248991 is an apocalyptic number.

64248991 is a deficient number, since it is larger than the sum of its proper divisors (47009).

64248991 is a wasteful number, since it uses less digits than its factorization.

64248991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47008.

The product of its digits is 124416, while the sum is 43.

The square root of 64248991 is about 8015.5468310029. The cubic root of 64248991 is about 400.5180599949.

The spelling of 64248991 in words is "sixty-four million, two hundred forty-eight thousand, nine hundred ninety-one".