21003023291 has 2 divisors, whose sum is σ = 21003023292. Its totient is φ = 21003023290.

The previous prime is 21003023287. The next prime is 21003023297. The reversal of 21003023291 is 19232030012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21003023291 - 2² = 21003023287 is a prime.

It is a super-2 number, since 2×21003023291² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21003023297) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10501511645 + 10501511646.

It is an arithmetic number, because the mean of its divisors is an integer number (10501511646).

Almost surely, 2^21003023291 is an apocalyptic number.

21003023291 is a deficient number, since it is larger than the sum of its proper divisors (1).

21003023291 is an equidigital number, since it uses as much as digits as its factorization.

21003023291 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 23.

The spelling of 21003023291 in words is "twenty-one billion, three million, twenty-three thousand, two hundred ninety-one".