2156739643 has 4 divisors (see below), whose sum is σ = 2157046920. Its totient is φ = 2156432368.

The previous prime is 2156739593. The next prime is 2156739671. The reversal of 2156739643 is 3469376512.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2156739643 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2156739593 and 2156739602.

It is not an unprimeable number, because it can be changed into a prime (2156739743) 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, 142858 + ... + 157231.

It is an arithmetic number, because the mean of its divisors is an integer number (539261730).

Almost surely, 2^2156739643 is an apocalyptic number.

2156739643 is a deficient number, since it is larger than the sum of its proper divisors (307277).

2156739643 is an equidigital number, since it uses as much as digits as its factorization.

2156739643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 307276.

The product of its digits is 816480, while the sum is 46.

The square root of 2156739643 is about 46440.7110518347. The cubic root of 2156739643 is about 1292.0100951887.

The spelling of 2156739643 in words is "two billion, one hundred fifty-six million, seven hundred thirty-nine thousand, six hundred forty-three".