20445643494 has 24 divisors (see below), whose sum is σ = 44492348160. Its totient is φ = 6785452368.

The previous prime is 20445643441. The next prime is 20445643511. The reversal of 20445643494 is 49434654402.

20445643494 is a `hidden beast` number, since 2 + 0 + 44 + 564 + 3 + 49 + 4 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2475942 + ... + 2484185.

It is an arithmetic number, because the mean of its divisors is an integer number (1853847840).

Almost surely, 2^20445643494 is an apocalyptic number.

20445643494 is an abundant number, since it is smaller than the sum of its proper divisors (24046704666).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20445643494 is a wasteful number, since it uses less digits than its factorization.

20445643494 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4960364 (or 4960361 counting only the distinct ones).

The product of its (nonzero) digits is 1658880, while the sum is 45.

The spelling of 20445643494 in words is "twenty billion, four hundred forty-five million, six hundred forty-three thousand, four hundred ninety-four".