21353692668 has 48 divisors (see below), whose sum is σ = 62119835904. Its totient is φ = 5546413440.

The previous prime is 21353692667. The next prime is 21353692733. The reversal of 21353692668 is 86629635312.

It is a self number, because there is not a number n which added to its sum of digits gives 21353692668.

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 pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11554105 + ... + 11555952.

It is an arithmetic number, because the mean of its divisors is an integer number (1294163248).

Almost surely, 2^21353692668 is an apocalyptic number.

21353692668 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21353692668 is an abundant number, since it is smaller than the sum of its proper divisors (40766143236).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21353692668 is a wasteful number, since it uses less digits than its factorization.

21353692668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23110082 (or 23110080 counting only the distinct ones).

The product of its digits is 2799360, while the sum is 51.

The spelling of 21353692668 in words is "twenty-one billion, three hundred fifty-three million, six hundred ninety-two thousand, six hundred sixty-eight".