21020233291 has 2 divisors, whose sum is σ = 21020233292. Its totient is φ = 21020233290.

The previous prime is 21020233277. The next prime is 21020233373. The reversal of 21020233291 is 19233202012.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21020233291 is a prime.

It is a super-3 number, since 3×21020233291³ (a number of 32 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (21020233211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510116645 + 10510116646.

It is an arithmetic number, because the mean of its divisors is an integer number (10510116646).

Almost surely, 2^21020233291 is an apocalyptic number.

21020233291 is a deficient number, since it is larger than the sum of its proper divisors (1).

21020233291 is an equidigital number, since it uses as much as digits as its factorization.

21020233291 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 25.

The spelling of 21020233291 in words is "twenty-one billion, twenty million, two hundred thirty-three thousand, two hundred ninety-one".