20905572 has 24 divisors (see below), whose sum is σ = 49970592. Its totient is φ = 6798400.

The previous prime is 20905559. The next prime is 20905579. The reversal of 20905572 is 27550902.

It is a happy number.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (20905579) 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, 20754 + ... + 21737.

It is an arithmetic number, because the mean of its divisors is an integer number (2082108).

Almost surely, 2^20905572 is an apocalyptic number.

It is an amenable number.

20905572 is an abundant number, since it is smaller than the sum of its proper divisors (29065020).

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

20905572 is a wasteful number, since it uses less digits than its factorization.

20905572 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42539 (or 42537 counting only the distinct ones).

The product of its (nonzero) digits is 6300, while the sum is 30.

The square root of 20905572 is about 4572.2611473974. The cubic root of 20905572 is about 275.4782729519.

The spelling of 20905572 in words is "twenty million, nine hundred five thousand, five hundred seventy-two".