20902647 has 4 divisors (see below), whose sum is σ = 27870200. Its totient is φ = 13935096.

The previous prime is 20902633. The next prime is 20902667. The reversal of 20902647 is 74620902.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 20902647 - 2⁸ = 20902391 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20902667) 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, 3483772 + ... + 3483777.

It is an arithmetic number, because the mean of its divisors is an integer number (6967550).

Almost surely, 2^20902647 is an apocalyptic number.

20902647 is a deficient number, since it is larger than the sum of its proper divisors (6967553).

20902647 is an equidigital number, since it uses as much as digits as its factorization.

20902647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6967552.

The product of its (nonzero) digits is 6048, while the sum is 30.

The square root of 20902647 is about 4571.9412725887. The cubic root of 20902647 is about 275.4654245188.

The spelling of 20902647 in words is "twenty million, nine hundred two thousand, six hundred forty-seven".