20920537 has 12 divisors (see below), whose sum is σ = 23561748. Its totient is φ = 18550400.

The previous prime is 20920519. The next prime is 20920541. The reversal of 20920537 is 73502902.

It can be written as a sum of positive squares in 2 ways, for example, as 9217296 + 11703241 = 3036^2 + 3421^2 .

It is a de Polignac number, because none of the positive numbers 2^k-20920537 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20920337) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2853 + ... + 7069.

It is an arithmetic number, because the mean of its divisors is an integer number (1963479).

Almost surely, 2^20920537 is an apocalyptic number.

It is an amenable number.

20920537 is a deficient number, since it is larger than the sum of its proper divisors (2641211).

20920537 is a wasteful number, since it uses less digits than its factorization.

20920537 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4280 (or 4269 counting only the distinct ones).

The product of its (nonzero) digits is 3780, while the sum is 28.

The square root of 20920537 is about 4573.8973534613. The cubic root of 20920537 is about 275.5439898663.

The spelling of 20920537 in words is "twenty million, nine hundred twenty thousand, five hundred thirty-seven".