664112621 has 2 divisors, whose sum is σ = 664112622. Its totient is φ = 664112620.

The previous prime is 664112549. The next prime is 664112627. The reversal of 664112621 is 126211466.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 598340521 + 65772100 = 24461^2 + 8110^2 .

It is a cyclic number.

It is not a de Polignac number, because 664112621 - 2¹⁰ = 664111597 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (664112627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332056310 + 332056311.

It is an arithmetic number, because the mean of its divisors is an integer number (332056311).

Almost surely, 2^664112621 is an apocalyptic number.

It is an amenable number.

664112621 is a deficient number, since it is larger than the sum of its proper divisors (1).

664112621 is an equidigital number, since it uses as much as digits as its factorization.

664112621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3456, while the sum is 29.

The square root of 664112621 is about 25770.3826320061. The cubic root of 664112621 is about 872.4634548722.

The spelling of 664112621 in words is "six hundred sixty-four million, one hundred twelve thousand, six hundred twenty-one".