20939755 has 4 divisors (see below), whose sum is σ = 25127712. Its totient is φ = 16751800.

The previous prime is 20939741. The next prime is 20939761. The reversal of 20939755 is 55793902.

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

It is not a de Polignac number, because 20939755 - 2⁷ = 20939627 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2093971 + ... + 2093980.

It is an arithmetic number, because the mean of its divisors is an integer number (6281928).

Almost surely, 2^20939755 is an apocalyptic number.

20939755 is a deficient number, since it is larger than the sum of its proper divisors (4187957).

20939755 is an equidigital number, since it uses as much as digits as its factorization.

20939755 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4187956.

The product of its (nonzero) digits is 85050, while the sum is 40.

The square root of 20939755 is about 4575.9977054190. The cubic root of 20939755 is about 275.6283373464.

The spelling of 20939755 in words is "twenty million, nine hundred thirty-nine thousand, seven hundred fifty-five".