20844457 has 4 divisors (see below), whose sum is σ = 20866896. Its totient is φ = 20822020.

The previous prime is 20844451. The next prime is 20844469. The reversal of 20844457 is 75444802.

It is a happy number.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20844457 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20844451) 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, 9763 + ... + 11704.

It is an arithmetic number, because the mean of its divisors is an integer number (5216724).

Almost surely, 2^20844457 is an apocalyptic number.

It is an amenable number.

20844457 is a deficient number, since it is larger than the sum of its proper divisors (22439).

20844457 is an equidigital number, since it uses as much as digits as its factorization.

20844457 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22438.

The product of its (nonzero) digits is 35840, while the sum is 34.

The square root of 20844457 is about 4565.5730198958. The cubic root of 20844457 is about 275.2095680785.

The spelling of 20844457 in words is "twenty million, eight hundred forty-four thousand, four hundred fifty-seven".