21103013031 has 4 divisors (see below), whose sum is σ = 28137350712. Its totient is φ = 14068675352.

The previous prime is 21103013017. The next prime is 21103013051. The reversal of 21103013031 is 13031030112.

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 21103013031 - 2¹¹ = 21103010983 is a prime.

It is a super-2 number, since 2×21103013031² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21103013031.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21103013051) 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, 3517168836 + ... + 3517168841.

It is an arithmetic number, because the mean of its divisors is an integer number (7034337678).

Almost surely, 2^21103013031 is an apocalyptic number.

21103013031 is a deficient number, since it is larger than the sum of its proper divisors (7034337681).

21103013031 is an equidigital number, since it uses as much as digits as its factorization.

21103013031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7034337680.

The product of its (nonzero) digits is 54, while the sum is 15.

Adding to 21103013031 its reverse (13031030112), we get a palindrome (34134043143).

The spelling of 21103013031 in words is "twenty-one billion, one hundred three million, thirteen thousand, thirty-one".