20442605 has 4 divisors (see below), whose sum is σ = 24531132. Its totient is φ = 16354080.

The previous prime is 20442599. The next prime is 20442629. The reversal of 20442605 is 50624402.

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 3087049 + 17355556 = 1757^2 + 4166^2 .

It is not a de Polignac number, because 20442605 - 2⁴ = 20442589 is a prime.

It is a Duffinian number.

It is a congruent 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, 2044256 + ... + 2044265.

It is an arithmetic number, because the mean of its divisors is an integer number (6132783).

Almost surely, 2^20442605 is an apocalyptic number.

It is an amenable number.

20442605 is a deficient number, since it is larger than the sum of its proper divisors (4088527).

20442605 is an equidigital number, since it uses as much as digits as its factorization.

20442605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4088526.

The product of its (nonzero) digits is 1920, while the sum is 23.

The square root of 20442605 is about 4521.3499090427. The cubic root of 20442605 is about 273.4295277458.

The spelling of 20442605 in words is "twenty million, four hundred forty-two thousand, six hundred five".