20457284 has 6 divisors (see below), whose sum is σ = 35800254. Its totient is φ = 10228640.

The previous prime is 20457277. The next prime is 20457299. The reversal of 20457284 is 48275402.

It can be written as a sum of positive squares in only one way, i.e., 20070400 + 386884 = 4480^2 + 622^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 20457284.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2557157 + ... + 2557164.

It is an arithmetic number, because the mean of its divisors is an integer number (5966709).

Almost surely, 2^20457284 is an apocalyptic number.

It is an amenable number.

20457284 is a deficient number, since it is larger than the sum of its proper divisors (15342970).

20457284 is a wasteful number, since it uses less digits than its factorization.

20457284 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5114325 (or 5114323 counting only the distinct ones).

The product of its (nonzero) digits is 17920, while the sum is 32.

The square root of 20457284 is about 4522.9729161250. The cubic root of 20457284 is about 273.4949582806.

The spelling of 20457284 in words is "twenty million, four hundred fifty-seven thousand, two hundred eighty-four".