20765620 has 24 divisors (see below), whose sum is σ = 44325288. Its totient is φ = 8169600.

The previous prime is 20765617. The next prime is 20765669. The reversal of 20765620 is 2656702.

It can be written as a sum of positive squares in 4 ways, for example, as 2155024 + 18610596 = 1468^2 + 4314^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7291 + ... + 9730.

It is an arithmetic number, because the mean of its divisors is an integer number (1846887).

Almost surely, 2^20765620 is an apocalyptic number.

20765620 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20765620 is an abundant number, since it is smaller than the sum of its proper divisors (23559668).

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

20765620 is a wasteful number, since it uses less digits than its factorization.

20765620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17091 (or 17089 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 28.

The square root of 20765620 is about 4556.9309847747. The cubic root of 20765620 is about 274.8621678436.

The spelling of 20765620 in words is "twenty million, seven hundred sixty-five thousand, six hundred twenty".