20708457 has 32 divisors (see below), whose sum is σ = 34704384. Its totient is φ = 10670400.

The previous prime is 20708453. The next prime is 20708473. The reversal of 20708457 is 75480702.

It is not a de Polignac number, because 20708457 - 2² = 20708453 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (20708453) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 35982 + ... + 36552.

It is an arithmetic number, because the mean of its divisors is an integer number (1084512).

Almost surely, 2^20708457 is an apocalyptic number.

It is an amenable number.

20708457 is a deficient number, since it is larger than the sum of its proper divisors (13995927).

20708457 is a wasteful number, since it uses less digits than its factorization.

20708457 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 749.

The product of its (nonzero) digits is 15680, while the sum is 33.

The square root of 20708457 is about 4550.6545683011. The cubic root of 20708457 is about 274.6097251792.

The spelling of 20708457 in words is "twenty million, seven hundred eight thousand, four hundred fifty-seven".