21657683426 has 16 divisors (see below), whose sum is σ = 34403473440. Its totient is φ = 10190080320.

The previous prime is 21657683381. The next prime is 21657683441. The reversal of 21657683426 is 62438675612.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 154805 + ... + 259383.

It is an arithmetic number, because the mean of its divisors is an integer number (2150217090).

Almost surely, 2^21657683426 is an apocalyptic number.

21657683426 is a deficient number, since it is larger than the sum of its proper divisors (12745790014).

21657683426 is a wasteful number, since it uses less digits than its factorization.

21657683426 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110689.

The product of its digits is 2903040, while the sum is 50.

The spelling of 21657683426 in words is "twenty-one billion, six hundred fifty-seven million, six hundred eighty-three thousand, four hundred twenty-six".