21353692669 has 4 divisors (see below), whose sum is σ = 21354050844. Its totient is φ = 21353334496.

The previous prime is 21353692667. The next prime is 21353692733. The reversal of 21353692669 is 96629635312.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9508200100 + 11845492569 = 97510^2 + 108837^2 .

It is a cyclic number.

It is not a de Polignac number, because 21353692669 - 2¹ = 21353692667 is a prime.

It is a super-2 number, since 2×21353692669² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21353692667) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 65752 + ... + 216865.

It is an arithmetic number, because the mean of its divisors is an integer number (5338512711).

Almost surely, 2^21353692669 is an apocalyptic number.

It is an amenable number.

21353692669 is a deficient number, since it is larger than the sum of its proper divisors (358175).

21353692669 is an equidigital number, since it uses as much as digits as its factorization.

21353692669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 358174.

The product of its digits is 3149280, while the sum is 52.

The spelling of 21353692669 in words is "twenty-one billion, three hundred fifty-three million, six hundred ninety-two thousand, six hundred sixty-nine".