21093786169 has 9 divisors (see below), whose sum is σ = 21207241381. Its totient is φ = 20980937020.

The previous prime is 21093786163. The next prime is 21093786221. The reversal of 21093786169 is 96168739012.

It is a happy number.

The square root of 21093786169 is 145237.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 21093786169 - 2³¹ = 18946302521 is a prime.

It is a super-2 number, since 2×21093786169² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21093786163) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 45168474 + ... + 45168940.

Almost surely, 2^21093786169 is an apocalyptic number.

21093786169 is the 145237-th square number.

21093786169 is the 72619-th centered octagonal number.

It is an amenable number.

21093786169 is a deficient number, since it is larger than the sum of its proper divisors (113455212).

21093786169 is an frugal number, since it uses more digits than its factorization.

21093786169 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1556 (or 778 counting only the distinct ones).

The product of its (nonzero) digits is 979776, while the sum is 52.

The spelling of 21093786169 in words is "twenty-one billion, ninety-three million, seven hundred eighty-six thousand, one hundred sixty-nine".