21151718699 has 8 divisors (see below), whose sum is σ = 22459388400. Its totient is φ = 19851099136.

The previous prime is 21151718647. The next prime is 21151718723. The reversal of 21151718699 is 99681715112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21151718699 - 2⁸ = 21151718443 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21151718639) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1756349 + ... + 1768350.

It is an arithmetic number, because the mean of its divisors is an integer number (2807423550).

Almost surely, 2^21151718699 is an apocalyptic number.

21151718699 is a deficient number, since it is larger than the sum of its proper divisors (1307669701).

21151718699 is a wasteful number, since it uses less digits than its factorization.

21151718699 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3525069.

The product of its digits is 272160, while the sum is 50.

The spelling of 21151718699 in words is "twenty-one billion, one hundred fifty-one million, seven hundred eighteen thousand, six hundred ninety-nine".