21699690653 has 16 divisors (see below), whose sum is σ = 23038525440. Its totient is φ = 20394159984.

The previous prime is 21699690641. The next prime is 21699690659. The reversal of 21699690653 is 35609699612.

It is not a de Polignac number, because 21699690653 - 2⁴ = 21699690637 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21699690659) 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, 4859900 + ... + 4864362.

It is an arithmetic number, because the mean of its divisors is an integer number (1439907840).

Almost surely, 2^21699690653 is an apocalyptic number.

21699690653 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21699690653 is a deficient number, since it is larger than the sum of its proper divisors (1338834787).

21699690653 is a wasteful number, since it uses less digits than its factorization.

21699690653 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8128.

The product of its (nonzero) digits is 4723920, while the sum is 56.

The spelling of 21699690653 in words is "twenty-one billion, six hundred ninety-nine million, six hundred ninety thousand, six hundred fifty-three".