20945641 has 4 divisors (see below), whose sum is σ = 21071232. Its totient is φ = 20820052.

The previous prime is 20945623. The next prime is 20945651. The reversal of 20945641 is 14654902.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 14654902 = 2 ⋅7327451.

It is a cyclic number.

It is not a de Polignac number, because 20945641 - 2⁵ = 20945609 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20945621) 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, 62545 + ... + 62878.

It is an arithmetic number, because the mean of its divisors is an integer number (5267808).

Almost surely, 2^20945641 is an apocalyptic number.

It is an amenable number.

20945641 is a deficient number, since it is larger than the sum of its proper divisors (125591).

20945641 is a wasteful number, since it uses less digits than its factorization.

20945641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125590.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 20945641 is about 4576.6407986645. The cubic root of 20945641 is about 275.6541605777.

The spelling of 20945641 in words is "twenty million, nine hundred forty-five thousand, six hundred forty-one".