20644253464 has 32 divisors (see below), whose sum is σ = 40805982000. Its totient is φ = 9764278272.

The previous prime is 20644253419. The next prime is 20644253471. The reversal of 20644253464 is 46435244602.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1392 + ... + 203200.

Almost surely, 2^20644253464 is an apocalyptic number.

It is an amenable number.

20644253464 is a deficient number, since it is larger than the sum of its proper divisors (20161728536).

20644253464 is a wasteful number, since it uses less digits than its factorization.

20644253464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 202507 (or 202503 counting only the distinct ones).

The product of its (nonzero) digits is 552960, while the sum is 40.

The spelling of 20644253464 in words is "twenty billion, six hundred forty-four million, two hundred fifty-three thousand, four hundred sixty-four".