2165947890 has 32 divisors (see below), whose sum is σ = 5228335296. Its totient is φ = 574246080.

The previous prime is 2165947871. The next prime is 2165947909. The reversal of 2165947890 is 987495612.

2165947890 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (2165947871) and next prime (2165947909).

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 203476 + ... + 213855.

It is an arithmetic number, because the mean of its divisors is an integer number (163385478).

Almost surely, 2^2165947890 is an apocalyptic number.

2165947890 is an abundant number, since it is smaller than the sum of its proper divisors (3062387406).

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

2165947890 is a wasteful number, since it uses less digits than its factorization.

2165947890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 417514.

The product of its (nonzero) digits is 1088640, while the sum is 51.

The square root of 2165947890 is about 46539.7452721864. The cubic root of 2165947890 is about 1293.8462396143.

The spelling of 2165947890 in words is "two billion, one hundred sixty-five million, nine hundred forty-seven thousand, eight hundred ninety".