20905144 has 16 divisors (see below), whose sum is σ = 42212520. Its totient is φ = 9648480.

The previous prime is 20905133. The next prime is 20905153. The reversal of 20905144 is 44150902.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 100402 + ... + 100609.

Almost surely, 2^20905144 is an apocalyptic number.

It is an amenable number.

20905144 is an abundant number, since it is smaller than the sum of its proper divisors (21307376).

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

20905144 is a wasteful number, since it uses less digits than its factorization.

20905144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 201030 (or 201026 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 20905144 is about 4572.2143431821. The cubic root of 20905144 is about 275.4763929825.

The spelling of 20905144 in words is "twenty million, nine hundred five thousand, one hundred forty-four".