21101303831 has 2 divisors, whose sum is σ = 21101303832. Its totient is φ = 21101303830.

The previous prime is 21101303819. The next prime is 21101303837. The reversal of 21101303831 is 13830310112.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21101303831 is a prime.

It is a super-2 number, since 2×21101303831² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21101303797 and 21101303806.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21101303837) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10550651915 + 10550651916.

It is an arithmetic number, because the mean of its divisors is an integer number (10550651916).

Almost surely, 2^21101303831 is an apocalyptic number.

21101303831 is a deficient number, since it is larger than the sum of its proper divisors (1).

21101303831 is an equidigital number, since it uses as much as digits as its factorization.

21101303831 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 432, while the sum is 23.

Adding to 21101303831 its reverse (13830310112), we get a palindrome (34931613943).

The spelling of 21101303831 in words is "twenty-one billion, one hundred one million, three hundred three thousand, eight hundred thirty-one".