646502123644 has 24 divisors (see below), whose sum is σ = 1246742918960. Its totient is φ = 291446394624.

The previous prime is 646502123591. The next prime is 646502123647. The reversal of 646502123644 is 446321205646.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is a self number, because there is not a number n which added to its sum of digits gives 646502123644.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646502123647) 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, 144564429 + ... + 144568900.

Almost surely, 2^646502123644 is an apocalyptic number.

It is an amenable number.

646502123644 is a deficient number, since it is larger than the sum of its proper divisors (600240795316).

646502123644 is a wasteful number, since it uses less digits than its factorization.

646502123644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 289133389 (or 289133387 counting only the distinct ones).

The product of its (nonzero) digits is 829440, while the sum is 43.

The spelling of 646502123644 in words is "six hundred forty-six billion, five hundred two million, one hundred twenty-three thousand, six hundred forty-four".