2191655872 has 56 divisors (see below), whose sum is σ = 5076163584. Its totient is φ = 919287552.

The previous prime is 2191655867. The next prime is 2191655881. The reversal of 2191655872 is 2785561912.

It is a tau number, because it is divible by the number of its divisors (56).

It is a super-2 number, since 2×2191655872² = 9606710922544160768, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30988 + ... + 73099.

Almost surely, 2^2191655872 is an apocalyptic number.

It is an amenable number.

2191655872 is an abundant number, since it is smaller than the sum of its proper divisors (2884507712).

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

2191655872 is a wasteful number, since it uses less digits than its factorization.

2191655872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104153 (or 104143 counting only the distinct ones).

The product of its digits is 302400, while the sum is 46.

The square root of 2191655872 is about 46815.1243937256. The cubic root of 2191655872 is about 1298.9450755420.

The spelling of 2191655872 in words is "two billion, one hundred ninety-one million, six hundred fifty-five thousand, eight hundred seventy-two".