21242684866 has 64 divisors (see below), whose sum is σ = 37874535552. Its totient is φ = 8843738112.

The previous prime is 21242684863. The next prime is 21242684867. The reversal of 21242684866 is 66848624212.

It is not an unprimeable number, because it can be changed into a prime (21242684863) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1086025 + ... + 1105411.

It is an arithmetic number, because the mean of its divisors is an integer number (591789618).

Almost surely, 2^21242684866 is an apocalyptic number.

21242684866 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21242684866 is a deficient number, since it is larger than the sum of its proper divisors (16631850686).

21242684866 is a wasteful number, since it uses less digits than its factorization.

21242684866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19523.

The product of its digits is 1769472, while the sum is 49.

The spelling of 21242684866 in words is "twenty-one billion, two hundred forty-two million, six hundred eighty-four thousand, eight hundred sixty-six".