64531999 has 12 divisors (see below), whose sum is σ = 77839824. Its totient is φ = 52399872.

The previous prime is 64531993. The next prime is 64532003. The reversal of 64531999 is 99913546.

It is not a de Polignac number, because 64531999 - 2⁷ = 64531871 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 (64531993) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10242 + ... + 15295.

It is an arithmetic number, because the mean of its divisors is an integer number (6486652).

Almost surely, 2^64531999 is an apocalyptic number.

64531999 is a deficient number, since it is larger than the sum of its proper divisors (13307825).

64531999 is a wasteful number, since it uses less digits than its factorization.

64531999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25582 (or 25563 counting only the distinct ones).

The product of its digits is 262440, while the sum is 46.

The square root of 64531999 is about 8033.1811258056. The cubic root of 64531999 is about 401.1052743585.

The spelling of 64531999 in words is "sixty-four million, five hundred thirty-one thousand, nine hundred ninety-nine".