21002042799 has 20 divisors (see below), whose sum is σ = 31443350400. Its totient is φ = 13970154240.

The previous prime is 21002042783. The next prime is 21002042807. The reversal of 21002042799 is 99724020012.

It is not a de Polignac number, because 21002042799 - 2⁴ = 21002042783 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002042729) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 252367 + ... + 325104.

It is an arithmetic number, because the mean of its divisors is an integer number (1572167520).

Almost surely, 2^21002042799 is an apocalyptic number.

21002042799 is a deficient number, since it is larger than the sum of its proper divisors (10441307601).

21002042799 is an equidigital number, since it uses as much as digits as its factorization.

21002042799 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 577932 (or 577923 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The spelling of 21002042799 in words is "twenty-one billion, two million, forty-two thousand, seven hundred ninety-nine".