21099599617 has 16 divisors (see below), whose sum is σ = 22480632000. Its totient is φ = 19746042624.

The previous prime is 21099599593. The next prime is 21099599663. The reversal of 21099599617 is 71699599012.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21099599617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21099099617) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2012134 + ... + 2022592.

It is an arithmetic number, because the mean of its divisors is an integer number (1405039500).

Almost surely, 2^21099599617 is an apocalyptic number.

It is an amenable number.

21099599617 is a deficient number, since it is larger than the sum of its proper divisors (1381032383).

21099599617 is a wasteful number, since it uses less digits than its factorization.

21099599617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11760.

The product of its (nonzero) digits is 2755620, while the sum is 58.

The spelling of 21099599617 in words is "twenty-one billion, ninety-nine million, five hundred ninety-nine thousand, six hundred seventeen".