21002309993 has 16 divisors (see below), whose sum is σ = 24365134080. Its totient is φ = 17730619200.

The previous prime is 21002309989. The next prime is 21002310011. The reversal of 21002309993 is 39990320012.

It is not a de Polignac number, because 21002309993 - 2² = 21002309989 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21002309893) 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 15 ways as a sum of consecutive naturals, for example, 486743 + ... + 528131.

It is an arithmetic number, because the mean of its divisors is an integer number (1522820880).

Almost surely, 2^21002309993 is an apocalyptic number.

It is an amenable number.

21002309993 is a deficient number, since it is larger than the sum of its proper divisors (3362824087).

21002309993 is a wasteful number, since it uses less digits than its factorization.

21002309993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42488.

The product of its (nonzero) digits is 26244, while the sum is 38.

The spelling of 21002309993 in words is "twenty-one billion, two million, three hundred nine thousand, nine hundred ninety-three".