2161994670 has 48 divisors (see below), whose sum is σ = 6132205872. Its totient is φ = 524119680.

The previous prime is 2161994647. The next prime is 2161994677. The reversal of 2161994670 is 764991612.

2161994670 is a `hidden beast` number, since 21 + 619 + 9 + 4 + 6 + 7 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161994677) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1090927 + ... + 1092906.

It is an arithmetic number, because the mean of its divisors is an integer number (127754289).

Almost surely, 2^2161994670 is an apocalyptic number.

2161994670 is an abundant number, since it is smaller than the sum of its proper divisors (3970211202).

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

2161994670 is a wasteful number, since it uses less digits than its factorization.

2161994670 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2183857 (or 2183854 counting only the distinct ones).

The product of its (nonzero) digits is 163296, while the sum is 45.

The square root of 2161994670 is about 46497.2544350739. The cubic root of 2161994670 is about 1293.0585977323.

The spelling of 2161994670 in words is "two billion, one hundred sixty-one million, nine hundred ninety-four thousand, six hundred seventy".