664124263421 has 4 divisors (see below), whose sum is σ = 664451581500. Its totient is φ = 663796945344.

The previous prime is 664124263417. The next prime is 664124263463. The reversal of 664124263421 is 124362421466.

664124263421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 405241735396 + 258882528025 = 636586^2 + 508805^2 .

It is a cyclic number.

It is not a de Polignac number, because 664124263421 - 2² = 664124263417 is a prime.

It is a super-2 number, since 2×664124263421² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664124268421) 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, 163655996 + ... + 163660053.

It is an arithmetic number, because the mean of its divisors is an integer number (166112895375).

Almost surely, 2^664124263421 is an apocalyptic number.

It is an amenable number.

664124263421 is a deficient number, since it is larger than the sum of its proper divisors (327318079).

664124263421 is a wasteful number, since it uses less digits than its factorization.

664124263421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 327318078.

The product of its digits is 331776, while the sum is 41.

Adding to 664124263421 its reverse (124362421466), we get a palindrome (788486684887).

The spelling of 664124263421 in words is "six hundred sixty-four billion, one hundred twenty-four million, two hundred sixty-three thousand, four hundred twenty-one".