20442657 has 4 divisors (see below), whose sum is σ = 27256880. Its totient is φ = 13628436.

The previous prime is 20442649. The next prime is 20442659. The reversal of 20442657 is 75624402.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 20442657 - 2³ = 20442649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20442659) 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, 3407107 + ... + 3407112.

It is an arithmetic number, because the mean of its divisors is an integer number (6814220).

Almost surely, 2^20442657 is an apocalyptic number.

It is an amenable number.

20442657 is a deficient number, since it is larger than the sum of its proper divisors (6814223).

20442657 is an equidigital number, since it uses as much as digits as its factorization.

20442657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6814222.

The product of its (nonzero) digits is 13440, while the sum is 30.

The square root of 20442657 is about 4521.3556595340. The cubic root of 20442657 is about 273.4297595871.

The spelling of 20442657 in words is "twenty million, four hundred forty-two thousand, six hundred fifty-seven".