21699254647 has 32 divisors (see below), whose sum is σ = 25906687488. Its totient is φ = 17788208256.

The previous prime is 21699254639. The next prime is 21699254651. The reversal of 21699254647 is 74645299612.

It is not a de Polignac number, because 21699254647 - 2³ = 21699254639 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21699254347) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10416268 + ... + 10418350.

It is an arithmetic number, because the mean of its divisors is an integer number (809583984).

Almost surely, 2^21699254647 is an apocalyptic number.

21699254647 is a deficient number, since it is larger than the sum of its proper divisors (4207432841).

21699254647 is a wasteful number, since it uses less digits than its factorization.

21699254647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2839.

The product of its digits is 6531840, while the sum is 55.

The spelling of 21699254647 in words is "twenty-one billion, six hundred ninety-nine million, two hundred fifty-four thousand, six hundred forty-seven".