2161001247 has 4 divisors (see below), whose sum is σ = 2881335000. Its totient is φ = 1440667496.

The previous prime is 2161001231. The next prime is 2161001263. The reversal of 2161001247 is 7421001612.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (2161001231) and next prime (2161001263).

It is a cyclic number.

It is not a de Polignac number, because 2161001247 - 2⁴ = 2161001231 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161001267) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 360166872 + ... + 360166877.

It is an arithmetic number, because the mean of its divisors is an integer number (720333750).

Almost surely, 2^2161001247 is an apocalyptic number.

2161001247 is a deficient number, since it is larger than the sum of its proper divisors (720333753).

2161001247 is an equidigital number, since it uses as much as digits as its factorization.

2161001247 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 720333752.

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 2161001247 is about 46486.5706091555. The cubic root of 2161001247 is about 1292.8605166165.

Adding to 2161001247 its reverse (7421001612), we get a palindrome (9582002859).

The spelling of 2161001247 in words is "two billion, one hundred sixty-one million, one thousand, two hundred forty-seven".