20920261 has 4 divisors (see below), whose sum is σ = 21112300. Its totient is φ = 20728224.

The previous prime is 20920259. The next prime is 20920301. The reversal of 20920261 is 16202902.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 17589636 + 3330625 = 4194^2 + 1825^2 .

It is a cyclic number.

It is not a de Polignac number, because 20920261 - 2¹ = 20920259 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20920201) 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, 95856 + ... + 96073.

It is an arithmetic number, because the mean of its divisors is an integer number (5278075).

Almost surely, 2^20920261 is an apocalyptic number.

It is an amenable number.

20920261 is a deficient number, since it is larger than the sum of its proper divisors (192039).

20920261 is a wasteful number, since it uses less digits than its factorization.

20920261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 192038.

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 20920261 is about 4573.8671821556. The cubic root of 20920261 is about 275.5427781307.

The spelling of 20920261 in words is "twenty million, nine hundred twenty thousand, two hundred sixty-one".