21755709189 has 16 divisors (see below), whose sum is σ = 32465946240. Its totient is φ = 14397936480.

The previous prime is 21755709181. The next prime is 21755709191. The reversal of 21755709189 is 98190755712.

21755709189 is a `hidden beast` number, since 2 + 1 + 7 + 557 + 0 + 9 + 1 + 89 = 666.

It is not a de Polignac number, because 21755709189 - 2³ = 21755709181 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21755709181) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2937057 + ... + 2944454.

It is an arithmetic number, because the mean of its divisors is an integer number (2029121640).

Almost surely, 2^21755709189 is an apocalyptic number.

It is an amenable number.

21755709189 is a deficient number, since it is larger than the sum of its proper divisors (10710237051).

21755709189 is a wasteful number, since it uses less digits than its factorization.

21755709189 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5881657 (or 5881651 counting only the distinct ones).

The product of its (nonzero) digits is 1587600, while the sum is 54.

The spelling of 21755709189 in words is "twenty-one billion, seven hundred fifty-five million, seven hundred nine thousand, one hundred eighty-nine".