20457407 has 4 divisors (see below), whose sum is σ = 20638560. Its totient is φ = 20276256.

The previous prime is 20457391. The next prime is 20457413. The reversal of 20457407 is 70475402.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 70475402 = 2 ⋅35237701.

It is a cyclic number.

It is not a de Polignac number, because 20457407 - 2⁴ = 20457391 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20457407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20457487) 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, 90407 + ... + 90632.

It is an arithmetic number, because the mean of its divisors is an integer number (5159640).

Almost surely, 2^20457407 is an apocalyptic number.

20457407 is a deficient number, since it is larger than the sum of its proper divisors (181153).

20457407 is a wasteful number, since it uses less digits than its factorization.

20457407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 181152.

The product of its (nonzero) digits is 7840, while the sum is 29.

The square root of 20457407 is about 4522.9865133560. The cubic root of 20457407 is about 273.4955064116.

The spelling of 20457407 in words is "twenty million, four hundred fifty-seven thousand, four hundred seven".