21211230091 has 2 divisors, whose sum is σ = 21211230092. Its totient is φ = 21211230090.

The previous prime is 21211230023. The next prime is 21211230107. The reversal of 21211230091 is 19003211212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21211230091 - 2²³ = 21202841483 is a prime.

It is a super-3 number, since 3×21211230091³ (a number of 32 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (21211530091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605615045 + 10605615046.

It is an arithmetic number, because the mean of its divisors is an integer number (10605615046).

Almost surely, 2^21211230091 is an apocalyptic number.

21211230091 is a deficient number, since it is larger than the sum of its proper divisors (1).

21211230091 is an equidigital number, since it uses as much as digits as its factorization.

21211230091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216, while the sum is 22.

The spelling of 21211230091 in words is "twenty-one billion, two hundred eleven million, two hundred thirty thousand, ninety-one".