20399331 has 8 divisors (see below), whose sum is σ = 28630720. Its totient is φ = 12883752.

The previous prime is 20399299. The next prime is 20399341. The reversal of 20399331 is 13399302.

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

It is not a de Polignac number, because 20399331 - 2⁵ = 20399299 is a prime.

It is a super-2 number, since 2×20399331² = 832265410495122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20399341) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 178885 + ... + 178998.

It is an arithmetic number, because the mean of its divisors is an integer number (3578840).

Almost surely, 2^20399331 is an apocalyptic number.

20399331 is a deficient number, since it is larger than the sum of its proper divisors (8231389).

20399331 is a wasteful number, since it uses less digits than its factorization.

20399331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 357905.

The product of its (nonzero) digits is 4374, while the sum is 30.

The square root of 20399331 is about 4516.5618561025. The cubic root of 20399331 is about 273.2364546947.

The spelling of 20399331 in words is "twenty million, three hundred ninety-nine thousand, three hundred thirty-one".