20641964 has 24 divisors (see below), whose sum is σ = 41522208. Its totient is φ = 8795520.

The previous prime is 20641937. The next prime is 20641969. The reversal of 20641964 is 46914602.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 20641964.

It is not an unprimeable number, because it can be changed into a prime (20641969) 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, 3032 + ... + 7104.

It is an arithmetic number, because the mean of its divisors is an integer number (1730092).

Almost surely, 2^20641964 is an apocalyptic number.

It is an amenable number.

20641964 is an abundant number, since it is smaller than the sum of its proper divisors (20880244).

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

20641964 is a wasteful number, since it uses less digits than its factorization.

20641964 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4265 (or 4263 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 32.

The square root of 20641964 is about 4543.3428221960. The cubic root of 20641964 is about 274.3154942968.

The spelling of 20641964 in words is "twenty million, six hundred forty-one thousand, nine hundred sixty-four".