20740457 has 16 divisors (see below), whose sum is σ = 23531520. Its totient is φ = 18176400.

The previous prime is 20740441. The next prime is 20740463. The reversal of 20740457 is 75404702.

It is a cyclic number.

It is not a de Polignac number, because 20740457 - 2⁴ = 20740441 is a prime.

It is a Smith number, since the sum of its digits (29) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20740417) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12782 + ... + 14312.

It is an arithmetic number, because the mean of its divisors is an integer number (1470720).

Almost surely, 2^20740457 is an apocalyptic number.

It is an amenable number.

20740457 is a deficient number, since it is larger than the sum of its proper divisors (2791063).

20740457 is a wasteful number, since it uses less digits than its factorization.

20740457 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1604.

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

The square root of 20740457 is about 4554.1691887764. The cubic root of 20740457 is about 274.7511004114.

The spelling of 20740457 in words is "twenty million, seven hundred forty thousand, four hundred fifty-seven".