20745820 has 24 divisors (see below), whose sum is σ = 44972928. Its totient is φ = 8030400.

The previous prime is 20745799. The next prime is 20745833. The reversal of 20745820 is 2854702.

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16111 + ... + 17350.

It is an arithmetic number, because the mean of its divisors is an integer number (1873872).

Almost surely, 2^20745820 is an apocalyptic number.

20745820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20745820 is an abundant number, since it is smaller than the sum of its proper divisors (24227108).

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

20745820 is a wasteful number, since it uses less digits than its factorization.

20745820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33501 (or 33499 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 28.

The square root of 20745820 is about 4554.7579518565. The cubic root of 20745820 is about 274.7747797862.

The spelling of 20745820 in words is "twenty million, seven hundred forty-five thousand, eight hundred twenty".