20399323 has 4 divisors (see below), whose sum is σ = 23313520. Its totient is φ = 17485128.

The previous prime is 20399299. The next prime is 20399341. The reversal of 20399323 is 32399302.

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 20399323 - 2¹³ = 20391131 is a prime.

It is a super-2 number, since 2×20399323² = 832264757716658, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20399723) 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, 1457088 + ... + 1457101.

It is an arithmetic number, because the mean of its divisors is an integer number (5828380).

Almost surely, 2^20399323 is an apocalyptic number.

20399323 is a deficient number, since it is larger than the sum of its proper divisors (2914197).

20399323 is an equidigital number, since it uses as much as digits as its factorization.

20399323 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2914196.

The product of its (nonzero) digits is 8748, while the sum is 31.

The square root of 20399323 is about 4516.5609704730. The cubic root of 20399323 is about 273.2364189763.

The spelling of 20399323 in words is "twenty million, three hundred ninety-nine thousand, three hundred twenty-three".