21100030901 has 2 divisors, whose sum is σ = 21100030902. Its totient is φ = 21100030900.

The previous prime is 21100030891. The next prime is 21100030909. The reversal of 21100030901 is 10903000112.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14416804900 + 6683226001 = 120070^2 + 81751^2 .

It is a cyclic number.

It is not a de Polignac number, because 21100030901 - 2²⁶ = 21032922037 is a prime.

It is a super-2 number, since 2×21100030901² (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 21100030901.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21100030909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10550015450 + 10550015451.

It is an arithmetic number, because the mean of its divisors is an integer number (10550015451).

Almost surely, 2^21100030901 is an apocalyptic number.

It is an amenable number.

21100030901 is a deficient number, since it is larger than the sum of its proper divisors (1).

21100030901 is an equidigital number, since it uses as much as digits as its factorization.

21100030901 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 54, while the sum is 17.

The spelling of 21100030901 in words is "twenty-one billion, one hundred million, thirty thousand, nine hundred one".