21366828868 has 36 divisors (see below), whose sum is σ = 47451014352. Its totient is φ = 8324737680.

The previous prime is 21366828817. The next prime is 21366828911. The reversal of 21366828868 is 86882866312.

It is a super-2 number, since 2×21366828868² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4953046 + ... + 4957357.

It is an arithmetic number, because the mean of its divisors is an integer number (1318083732).

Almost surely, 2^21366828868 is an apocalyptic number.

21366828868 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21366828868 is an abundant number, since it is smaller than the sum of its proper divisors (26084185484).

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

21366828868 is a wasteful number, since it uses less digits than its factorization.

21366828868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9910432 (or 9910423 counting only the distinct ones).

The product of its digits is 10616832, while the sum is 58.

The spelling of 21366828868 in words is "twenty-one billion, three hundred sixty-six million, eight hundred twenty-eight thousand, eight hundred sixty-eight".