21643662122 has 16 divisors (see below), whose sum is σ = 32587236360. Its totient is φ = 10781275392.

The previous prime is 21643662121. The next prime is 21643662137. The reversal of 21643662122 is 22126634612.

It can be written as a sum of positive squares in 4 ways, for example, as 15800741401 + 5842920721 = 125701^2 + 76439^2 .

It is a super-2 number, since 2×21643662122² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21643662121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2908118 + ... + 2915550.

Almost surely, 2^21643662122 is an apocalyptic number.

21643662122 is a deficient number, since it is larger than the sum of its proper divisors (10943574238).

21643662122 is a wasteful number, since it uses less digits than its factorization.

21643662122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12697.

The product of its digits is 41472, while the sum is 35.

The spelling of 21643662122 in words is "twenty-one billion, six hundred forty-three million, six hundred sixty-two thousand, one hundred twenty-two".