20397287 has 8 divisors (see below), whose sum is σ = 21294720. Its totient is φ = 19514880.

The previous prime is 20397269. The next prime is 20397313. The reversal of 20397287 is 78279302.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20397287 - 2⁸ = 20397031 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20397287.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20397217) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 938 + ... + 6455.

It is an arithmetic number, because the mean of its divisors is an integer number (2661840).

Almost surely, 2^20397287 is an apocalyptic number.

20397287 is a deficient number, since it is larger than the sum of its proper divisors (897433).

20397287 is an equidigital number, since it uses as much as digits as its factorization.

20397287 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7513.

The product of its (nonzero) digits is 42336, while the sum is 38.

The square root of 20397287 is about 4516.3355721204. The cubic root of 20397287 is about 273.2273283501.

The spelling of 20397287 in words is "twenty million, three hundred ninety-seven thousand, two hundred eighty-seven".