21901818384331 has 2 divisors, whose sum is σ = 21901818384332. Its totient is φ = 21901818384330.

The previous prime is 21901818384269. The next prime is 21901818384371. The reversal of 21901818384331 is 13348381810912.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21901818384331 - 2²¹ = 21901816287179 is a prime.

It is a super-2 number, since 2×21901818384331² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21901818384371) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10950909192165 + 10950909192166.

It is an arithmetic number, because the mean of its divisors is an integer number (10950909192166).

Almost surely, 2^{21901818384331} is an apocalyptic number.

21901818384331 is a deficient number, since it is larger than the sum of its proper divisors (1).

21901818384331 is an equidigital number, since it uses as much as digits as its factorization.

21901818384331 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 995328, while the sum is 52.

The spelling of 21901818384331 in words is "twenty-one trillion, nine hundred one billion, eight hundred eighteen million, three hundred eighty-four thousand, three hundred thirty-one".