21699970209 has 24 divisors (see below), whose sum is σ = 32366011392. Its totient is φ = 13995437760.

The previous prime is 21699970207. The next prime is 21699970217. The reversal of 21699970209 is 90207999612.

It is not a de Polignac number, because 21699970209 - 2¹ = 21699970207 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21699970207) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 991624 + ... + 1013270.

It is an arithmetic number, because the mean of its divisors is an integer number (1348583808).

Almost surely, 2^21699970209 is an apocalyptic number.

It is an amenable number.

21699970209 is a deficient number, since it is larger than the sum of its proper divisors (10666041183).

21699970209 is a wasteful number, since it uses less digits than its factorization.

21699970209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25277 (or 25274 counting only the distinct ones).

The product of its (nonzero) digits is 1102248, while the sum is 54.

The spelling of 21699970209 in words is "twenty-one billion, six hundred ninety-nine million, nine hundred seventy thousand, two hundred nine".