2161987266 has 8 divisors (see below), whose sum is σ = 4323974544. Its totient is φ = 720662420.

The previous prime is 2161987259. The next prime is 2161987279. The reversal of 2161987266 is 6627891612.

It is a sphenic number, since it is the product of 3 distinct primes.

2161987266 is an admirable number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 180165600 + ... + 180165611.

It is an arithmetic number, because the mean of its divisors is an integer number (540496818).

Almost surely, 2^2161987266 is an apocalyptic number.

2161987266 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

2161987266 is a wasteful number, since it uses less digits than its factorization.

2161987266 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 360331216.

The product of its digits is 435456, while the sum is 48.

The square root of 2161987266 is about 46497.1748174015. The cubic root of 2161987266 is about 1293.0571216545.

The spelling of 2161987266 in words is "two billion, one hundred sixty-one million, nine hundred eighty-seven thousand, two hundred sixty-six".