20501331 has 4 divisors (see below), whose sum is σ = 27335112. Its totient is φ = 13667552.

The previous prime is 20501329. The next prime is 20501333. The reversal of 20501331 is 13310502.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (20501329) and next prime (20501333).

It is a cyclic number.

It is not a de Polignac number, because 20501331 - 2¹ = 20501329 is a prime.

It is a super-2 number, since 2×20501331² = 840609145543122, 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 20501331.

It is not an unprimeable number, because it can be changed into a prime (20501333) 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, 3416886 + ... + 3416891.

It is an arithmetic number, because the mean of its divisors is an integer number (6833778).

Almost surely, 2^20501331 is an apocalyptic number.

20501331 is a deficient number, since it is larger than the sum of its proper divisors (6833781).

20501331 is an equidigital number, since it uses as much as digits as its factorization.

20501331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6833780.

The product of its (nonzero) digits is 90, while the sum is 15.

The square root of 20501331 is about 4527.8395510442. The cubic root of 20501331 is about 273.6911067821.

Adding to 20501331 its reverse (13310502), we get a palindrome (33811833).

The spelling of 20501331 in words is "twenty million, five hundred one thousand, three hundred thirty-one".