21415320331 has 4 divisors (see below), whose sum is σ = 21449259664. Its totient is φ = 21381381000.

The previous prime is 21415320323. The next prime is 21415320341. The reversal of 21415320331 is 13302351412.

It is a happy number.

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 21415320331 - 2³ = 21415320323 is a prime.

It is a super-2 number, since 2×21415320331² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21415320296 and 21415320305.

It is not an unprimeable number, because it can be changed into a prime (21415320341) 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, 16968720 + ... + 16969981.

It is an arithmetic number, because the mean of its divisors is an integer number (5362314916).

Almost surely, 2^21415320331 is an apocalyptic number.

21415320331 is a deficient number, since it is larger than the sum of its proper divisors (33939333).

21415320331 is an equidigital number, since it uses as much as digits as its factorization.

21415320331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33939332.

The product of its (nonzero) digits is 2160, while the sum is 25.

Adding to 21415320331 its reverse (13302351412), we get a palindrome (34717671743).

The spelling of 21415320331 in words is "twenty-one billion, four hundred fifteen million, three hundred twenty thousand, three hundred thirty-one".