664034021 has 8 divisors (see below), whose sum is σ = 798838080. Its totient is φ = 539215488.

The previous prime is 664034009. The next prime is 664034039. The reversal of 664034021 is 120430466.

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

It is not a de Polignac number, because 664034021 - 2¹⁸ = 663771877 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 (664034071) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2496236 + ... + 2496501.

It is an arithmetic number, because the mean of its divisors is an integer number (99854760).

Almost surely, 2^664034021 is an apocalyptic number.

It is an amenable number.

664034021 is a deficient number, since it is larger than the sum of its proper divisors (134804059).

664034021 is a wasteful number, since it uses less digits than its factorization.

664034021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4992763.

The product of its (nonzero) digits is 3456, while the sum is 26.

The square root of 664034021 is about 25768.8575804206. The cubic root of 664034021 is about 872.4290338363.

Adding to 664034021 its reverse (120430466), we get a palindrome (784464487).

The spelling of 664034021 in words is "six hundred sixty-four million, thirty-four thousand, twenty-one".