20169211491 has 80 divisors (see below), whose sum is σ = 35450731008. Its totient is φ = 11266257600.

The previous prime is 20169211483. The next prime is 20169211507. The reversal of 20169211491 is 19411296102.

It is a happy number.

20169211491 is a `hidden beast` number, since 2 + 0 + 169 + 2 + 1 + 1 + 491 = 666.

It is not a de Polignac number, because 20169211491 - 2³ = 20169211483 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20169211441) by changing a digit.

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 79 ways as a sum of consecutive naturals, for example, 13562950 + ... + 13564436.

Almost surely, 2^20169211491 is an apocalyptic number.

20169211491 is a deficient number, since it is larger than the sum of its proper divisors (15281519517).

20169211491 is a wasteful number, since it uses less digits than its factorization.

20169211491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2694 (or 2685 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 36.

The spelling of 20169211491 in words is "twenty billion, one hundred sixty-nine million, two hundred eleven thousand, four hundred ninety-one".