2161213237 has 4 divisors (see below), whose sum is σ = 2161310656. Its totient is φ = 2161115820.

The previous prime is 2161213217. The next prime is 2161213289. The reversal of 2161213237 is 7323121612.

2161213237 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2161213237 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161213207) 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, 2548 + ... + 65794.

It is an arithmetic number, because the mean of its divisors is an integer number (540327664).

Almost surely, 2^2161213237 is an apocalyptic number.

It is an amenable number.

2161213237 is a deficient number, since it is larger than the sum of its proper divisors (97419).

2161213237 is an equidigital number, since it uses as much as digits as its factorization.

2161213237 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97418.

The product of its digits is 3024, while the sum is 28.

The square root of 2161213237 is about 46488.8506741133. The cubic root of 2161213237 is about 1292.9027909311.

Adding to 2161213237 its reverse (7323121612), we get a palindrome (9484334849).

The spelling of 2161213237 in words is "two billion, one hundred sixty-one million, two hundred thirteen thousand, two hundred thirty-seven".