21189287821689 has 48 divisors (see below), whose sum is σ = 33088964388480. Its totient is φ = 12988991312640.

The previous prime is 21189287821687. The next prime is 21189287821697. The reversal of 21189287821689 is 98612878298112.

21189287821689 is a `hidden beast` number, since 2 + 1 + 189 + 287 + 8 + 2 + 168 + 9 = 666.

It is not a de Polignac number, because 21189287821689 - 2¹ = 21189287821687 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21189287821687) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 787077949 + ... + 787104869.

It is an arithmetic number, because the mean of its divisors is an integer number (689353424760).

Almost surely, 2^{21189287821689} is an apocalyptic number.

It is an amenable number.

21189287821689 is a deficient number, since it is larger than the sum of its proper divisors (11899676566791).

21189287821689 is a wasteful number, since it uses less digits than its factorization.

21189287821689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52782 (or 52779 counting only the distinct ones).

The product of its digits is 111476736, while the sum is 72.

The spelling of 21189287821689 in words is "twenty-one trillion, one hundred eighty-nine billion, two hundred eighty-seven million, eight hundred twenty-one thousand, six hundred eighty-nine".