20259647 has 4 divisors (see below), whose sum is σ = 20913216. Its totient is φ = 19606080.

The previous prime is 20259641. The next prime is 20259649. The reversal of 20259647 is 74695202.

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

It is a cyclic number.

It is not a de Polignac number, because 20259647 - 2¹⁴ = 20243263 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 (20259641) 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, 326738 + ... + 326799.

It is an arithmetic number, because the mean of its divisors is an integer number (5228304).

Almost surely, 2^20259647 is an apocalyptic number.

20259647 is a deficient number, since it is larger than the sum of its proper divisors (653569).

20259647 is an equidigital number, since it uses as much as digits as its factorization.

20259647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 653568.

The product of its (nonzero) digits is 30240, while the sum is 35.

The square root of 20259647 is about 4501.0717612586. The cubic root of 20259647 is about 272.6113654172.

The spelling of 20259647 in words is "twenty million, two hundred fifty-nine thousand, six hundred forty-seven".