2156382821 has 4 divisors (see below), whose sum is σ = 2156518272. Its totient is φ = 2156247372.

The previous prime is 2156382803. The next prime is 2156382863. The reversal of 2156382821 is 1282836512.

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 not a de Polignac number, because 2156382821 - 2²² = 2152188517 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 (2156382521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40085 + ... + 76938.

It is an arithmetic number, because the mean of its divisors is an integer number (539129568).

Almost surely, 2^2156382821 is an apocalyptic number.

It is an amenable number.

2156382821 is a deficient number, since it is larger than the sum of its proper divisors (135451).

2156382821 is a wasteful number, since it uses less digits than its factorization.

2156382821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135450.

The product of its digits is 46080, while the sum is 38.

The square root of 2156382821 is about 46436.8691989458. The cubic root of 2156382821 is about 1291.9388390136.

The spelling of 2156382821 in words is "two billion, one hundred fifty-six million, three hundred eighty-two thousand, eight hundred twenty-one".