2156132261 has 4 divisors (see below), whose sum is σ = 2156274624. Its totient is φ = 2155989900.

The previous prime is 2156132239. The next prime is 2156132311. The reversal of 2156132261 is 1622316512.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2156132261 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 (2156132221) 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, 45335 + ... + 79796.

It is an arithmetic number, because the mean of its divisors is an integer number (539068656).

Almost surely, 2^2156132261 is an apocalyptic number.

It is an amenable number.

2156132261 is a deficient number, since it is larger than the sum of its proper divisors (142363).

2156132261 is a wasteful number, since it uses less digits than its factorization.

2156132261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142362.

The product of its digits is 4320, while the sum is 29.

The square root of 2156132261 is about 46434.1712642748. The cubic root of 2156132261 is about 1291.8887983110. Note that the first 3 decimals are identical.

Adding to 2156132261 its reverse (1622316512), we get a palindrome (3778448773).

The spelling of 2156132261 in words is "two billion, one hundred fifty-six million, one hundred thirty-two thousand, two hundred sixty-one".