2161291400 has 24 divisors (see below), whose sum is σ = 5025002970. Its totient is φ = 864516480.

The previous prime is 2161291373. The next prime is 2161291421. The reversal of 2161291400 is 41921612.

It can be written as a sum of positive squares in 3 ways, for example, as 953450884 + 1207840516 = 30878^2 + 34754^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 2161291400.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5403029 + ... + 5403428.

Almost surely, 2^2161291400 is an apocalyptic number.

2161291400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2161291400 is an abundant number, since it is smaller than the sum of its proper divisors (2863711570).

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

2161291400 is a wasteful number, since it uses less digits than its factorization.

2161291400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10806473 (or 10806464 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 2161291400 is about 46489.6913304444. The cubic root of 2161291400 is about 1292.9183772294.

The spelling of 2161291400 in words is "two billion, one hundred sixty-one million, two hundred ninety-one thousand, four hundred".