20439955 has 4 divisors (see below), whose sum is σ = 24527952. Its totient is φ = 16351960.

The previous prime is 20439931. The next prime is 20439959. The reversal of 20439955 is 55993402.

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

It is not a de Polignac number, because 20439955 - 2²¹ = 18342803 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20439959) 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, 2043991 + ... + 2044000.

It is an arithmetic number, because the mean of its divisors is an integer number (6131988).

Almost surely, 2^20439955 is an apocalyptic number.

20439955 is a deficient number, since it is larger than the sum of its proper divisors (4087997).

20439955 is an equidigital number, since it uses as much as digits as its factorization.

20439955 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4087996.

The product of its (nonzero) digits is 48600, while the sum is 37.

The square root of 20439955 is about 4521.0568454732. The cubic root of 20439955 is about 273.4177122334.

The spelling of 20439955 in words is "twenty million, four hundred thirty-nine thousand, nine hundred fifty-five".