21102739091 has 32 divisors (see below), whose sum is σ = 24556105728. Its totient is φ = 17763338880.

The previous prime is 21102739043. The next prime is 21102739093. The reversal of 21102739091 is 19093720112.

It is not a de Polignac number, because 21102739091 - 2¹⁸ = 21102476947 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21102739093) 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 in 31 ways as a sum of consecutive naturals, for example, 50125061 + ... + 50125481.

It is an arithmetic number, because the mean of its divisors is an integer number (767378304).

Almost surely, 2^21102739091 is an apocalyptic number.

21102739091 is a deficient number, since it is larger than the sum of its proper divisors (3453366637).

21102739091 is a wasteful number, since it uses less digits than its factorization.

21102739091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1011.

The product of its (nonzero) digits is 6804, while the sum is 35.

The spelling of 21102739091 in words is "twenty-one billion, one hundred two million, seven hundred thirty-nine thousand, ninety-one".