21310102421 has 2 divisors, whose sum is σ = 21310102422. Its totient is φ = 21310102420.

The previous prime is 21310102409. The next prime is 21310102481. The reversal of 21310102421 is 12420101312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18738598321 + 2571504100 = 136889^2 + 50710^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21310102421 is a prime.

It is a super-2 number, since 2×21310102421² (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 21310102421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21310102481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10655051210 + 10655051211.

It is an arithmetic number, because the mean of its divisors is an integer number (10655051211).

Almost surely, 2^21310102421 is an apocalyptic number.

It is an amenable number.

21310102421 is a deficient number, since it is larger than the sum of its proper divisors (1).

21310102421 is an equidigital number, since it uses as much as digits as its factorization.

21310102421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 21310102421 its reverse (12420101312), we get a palindrome (33730203733).

The spelling of 21310102421 in words is "twenty-one billion, three hundred ten million, one hundred two thousand, four hundred twenty-one".