20402331 has 4 divisors (see below), whose sum is σ = 27203112. Its totient is φ = 13601552.

The previous prime is 20402321. The next prime is 20402351. The reversal of 20402331 is 13320402.

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 20402331 - 2⁶ = 20402267 is a prime.

It is a super-2 number, since 2×20402331² = 832510220467122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20402331.

It is not an unprimeable number, because it can be changed into a prime (20402321) 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 3 ways as a sum of consecutive naturals, for example, 3400386 + ... + 3400391.

It is an arithmetic number, because the mean of its divisors is an integer number (6800778).

Almost surely, 2^20402331 is an apocalyptic number.

20402331 is a deficient number, since it is larger than the sum of its proper divisors (6800781).

20402331 is an equidigital number, since it uses as much as digits as its factorization.

20402331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6800780.

The product of its (nonzero) digits is 144, while the sum is 15.

The square root of 20402331 is about 4516.8939549208. The cubic root of 20402331 is about 273.2498484212.

Adding to 20402331 its reverse (13320402), we get a palindrome (33722733).

It can be divided in two parts, 2040 and 2331, that added together give a triangular number (4371 = T₉₃).

The spelling of 20402331 in words is "twenty million, four hundred two thousand, three hundred thirty-one".