20457013 has 6 divisors (see below), whose sum is σ = 20599286. Its totient is φ = 20315592.

The previous prime is 20456987. The next prime is 20457023. The reversal of 20457013 is 31075402.

It can be written as a sum of positive squares in only one way, i.e., 18601969 + 1855044 = 4313^2 + 1362^2 .

It is not a de Polignac number, because 20457013 - 2⁵ = 20456981 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20457023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 51331 + ... + 51727.

Almost surely, 2^20457013 is an apocalyptic number.

It is an amenable number.

20457013 is a deficient number, since it is larger than the sum of its proper divisors (142273).

20457013 is an frugal number, since it uses more digits than its factorization.

20457013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 851 (or 624 counting only the distinct ones).

The product of its (nonzero) digits is 840, while the sum is 22.

The square root of 20457013 is about 4522.9429578539. The cubic root of 20457013 is about 273.4937506022.

The spelling of 20457013 in words is "twenty million, four hundred fifty-seven thousand, thirteen".