20320351 has 4 divisors (see below), whose sum is σ = 20336992. Its totient is φ = 20303712.

The previous prime is 20320343. The next prime is 20320361. The reversal of 20320351 is 15302302.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15302302 = 2 ⋅7651151.

It is a cyclic number.

It is not a de Polignac number, because 20320351 - 2³ = 20320343 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 (20320361) 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, 6330 + ... + 8983.

It is an arithmetic number, because the mean of its divisors is an integer number (5084248).

Almost surely, 2^20320351 is an apocalyptic number.

20320351 is a deficient number, since it is larger than the sum of its proper divisors (16641).

20320351 is a wasteful number, since it uses less digits than its factorization.

20320351 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16640.

The product of its (nonzero) digits is 180, while the sum is 16.

The square root of 20320351 is about 4507.8100004326. The cubic root of 20320351 is about 272.8833691625.

Adding to 20320351 its reverse (15302302), we get a palindrome (35622653).

The spelling of 20320351 in words is "twenty million, three hundred twenty thousand, three hundred fifty-one".