20920816 has 20 divisors (see below), whose sum is σ = 46324912. Its totient is φ = 8966016.

The previous prime is 20920811. The next prime is 20920819. The reversal of 20920816 is 61802902.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20920811) 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, 93285 + ... + 93508.

Almost surely, 2^20920816 is an apocalyptic number.

It is an amenable number.

20920816 is an abundant number, since it is smaller than the sum of its proper divisors (25404096).

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

20920816 is a wasteful number, since it uses less digits than its factorization.

20920816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 186808 (or 186802 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 20920816 is about 4573.9278525136. The cubic root of 20920816 is about 275.5452147621.

It can be divided in two parts, 20920 and 816, that added together give a triangular number (21736 = T₂₀₈).

The spelling of 20920816 in words is "twenty million, nine hundred twenty thousand, eight hundred sixteen".