664733337421 has 2 divisors, whose sum is σ = 664733337422. Its totient is φ = 664733337420.

The previous prime is 664733337353. The next prime is 664733337517. The reversal of 664733337421 is 124733337466.

664733337421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 653205020521 + 11528316900 = 808211^2 + 107370^2 .

It is a cyclic number.

It is not a de Polignac number, because 664733337421 - 2⁹ = 664733336909 is a prime.

It is a super-2 number, since 2×664733337421² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (664733937421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332366668710 + 332366668711.

It is an arithmetic number, because the mean of its divisors is an integer number (332366668711).

Almost surely, 2^664733337421 is an apocalyptic number.

It is an amenable number.

664733337421 is a deficient number, since it is larger than the sum of its proper divisors (1).

664733337421 is an equidigital number, since it uses as much as digits as its factorization.

664733337421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4572288, while the sum is 49.

The spelling of 664733337421 in words is "six hundred sixty-four billion, seven hundred thirty-three million, three hundred thirty-seven thousand, four hundred twenty-one".