20345287 has 8 divisors (see below), whose sum is σ = 20796032. Its totient is φ = 19899000.

The previous prime is 20345279. The next prime is 20345293. The reversal of 20345287 is 78254302.

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

It is not a de Polignac number, because 20345287 - 2³ = 20345279 is a prime.

It is a super-2 number, since 2×20345287² = 827861406224738, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20345267) 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, 9112 + ... + 11122.

It is an arithmetic number, because the mean of its divisors is an integer number (2599504).

Almost surely, 2^20345287 is an apocalyptic number.

20345287 is a deficient number, since it is larger than the sum of its proper divisors (450745).

20345287 is a wasteful number, since it uses less digits than its factorization.

20345287 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2229.

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

The square root of 20345287 is about 4510.5750187753. The cubic root of 20345287 is about 272.9949459453.

Adding to 20345287 its reverse (78254302), we get a palindrome (98599589).

The spelling of 20345287 in words is "twenty million, three hundred forty-five thousand, two hundred eighty-seven".