21898009862784 has 96 divisors (see below), whose sum is σ = 68742332137440. Its totient is φ = 6635760560640.

The previous prime is 21898009862779. The next prime is 21898009862857. The reversal of 21898009862784 is 48726890089812.

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-3 number, since 3×21898009862784³ (a number of 41 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 864018652 + ... + 864043995.

It is an arithmetic number, because the mean of its divisors is an integer number (716065959765).

Almost surely, 2^{21898009862784} is an apocalyptic number.

21898009862784 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21898009862784 is an abundant number, since it is smaller than the sum of its proper divisors (46844322274656).

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

21898009862784 is a wasteful number, since it uses less digits than its factorization.

21898009862784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1728062678 (or 1728062663 counting only the distinct ones).

The product of its (nonzero) digits is 222953472, while the sum is 72.

The spelling of 21898009862784 in words is "twenty-one trillion, eight hundred ninety-eight billion, nine million, eight hundred sixty-two thousand, seven hundred eighty-four".