20943644 has 12 divisors (see below), whose sum is σ = 36703464. Its totient is φ = 10456944.

The previous prime is 20943641. The next prime is 20943667. The reversal of 20943644 is 44634902.

It is a self number, because there is not a number n which added to its sum of digits gives 20943644.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20943641) 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, 179 + ... + 6474.

It is an arithmetic number, because the mean of its divisors is an integer number (3058622).

Almost surely, 2^20943644 is an apocalyptic number.

It is an amenable number.

20943644 is a deficient number, since it is larger than the sum of its proper divisors (15759820).

20943644 is a wasteful number, since it uses less digits than its factorization.

20943644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7444 (or 7442 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 32.

The square root of 20943644 is about 4576.4226203444. The cubic root of 20943644 is about 275.6453998232.

The spelling of 20943644 in words is "twenty million, nine hundred forty-three thousand, six hundred forty-four".