20670457 has 4 divisors (see below), whose sum is σ = 21229156. Its totient is φ = 20111760.

The previous prime is 20670449. The next prime is 20670467. The reversal of 20670457 is 75407602.

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 12467961 + 8202496 = 3531^2 + 2864^2 .

It is a cyclic number.

It is not a de Polignac number, because 20670457 - 2³ = 20670449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20670427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 279294 + ... + 279367.

It is an arithmetic number, because the mean of its divisors is an integer number (5307289).

Almost surely, 2^20670457 is an apocalyptic number.

It is an amenable number.

20670457 is a deficient number, since it is larger than the sum of its proper divisors (558699).

20670457 is an equidigital number, since it uses as much as digits as its factorization.

20670457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 558698.

The product of its (nonzero) digits is 11760, while the sum is 31.

The square root of 20670457 is about 4546.4774276356. The cubic root of 20670457 is about 274.4416528000.

The spelling of 20670457 in words is "twenty million, six hundred seventy thousand, four hundred fifty-seven".