664251023 has 4 divisors (see below), whose sum is σ = 664895088. Its totient is φ = 663606960.

The previous prime is 664251019. The next prime is 664251037. The reversal of 664251023 is 320152466.

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 664251023 - 2² = 664251019 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 (664251083) 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, 320483 + ... + 322548.

It is an arithmetic number, because the mean of its divisors is an integer number (166223772).

Almost surely, 2^664251023 is an apocalyptic number.

664251023 is a deficient number, since it is larger than the sum of its proper divisors (644065).

664251023 is a wasteful number, since it uses less digits than its factorization.

664251023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 644064.

The product of its (nonzero) digits is 8640, while the sum is 29.

The square root of 664251023 is about 25773.0677840260. The cubic root of 664251023 is about 872.5240581977.

The spelling of 664251023 in words is "six hundred sixty-four million, two hundred fifty-one thousand, twenty-three".