20284357 has 4 divisors (see below), whose sum is σ = 20432556. Its totient is φ = 20136160.

The previous prime is 20284339. The next prime is 20284373. The reversal of 20284357 is 75348202.

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 7568001 + 12716356 = 2751^2 + 3566^2 .

It is a cyclic number.

It is not a de Polignac number, because 20284357 - 2²³ = 11895749 is a prime.

It is a super-2 number, since 2×20284357² = 822910277806898, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) 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 a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20284337) 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, 73894 + ... + 74167.

It is an arithmetic number, because the mean of its divisors is an integer number (5108139).

Almost surely, 2^20284357 is an apocalyptic number.

It is an amenable number.

20284357 is a deficient number, since it is larger than the sum of its proper divisors (148199).

20284357 is a wasteful number, since it uses less digits than its factorization.

20284357 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 148198.

The product of its (nonzero) digits is 13440, while the sum is 31.

The square root of 20284357 is about 4503.8158266075. The cubic root of 20284357 is about 272.7221519813.

The spelling of 20284357 in words is "twenty million, two hundred eighty-four thousand, three hundred fifty-seven".