2056189781 has 4 divisors (see below), whose sum is σ = 2104008192. Its totient is φ = 2008371372.

The previous prime is 2056189777. The next prime is 2056189787. The reversal of 2056189781 is 1879816502.

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 2056189781 - 2² = 2056189777 is a prime.

It is a super-2 number, since 2×2056189781² = 8455832830977655922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2056189787) 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, 23909141 + ... + 23909226.

It is an arithmetic number, because the mean of its divisors is an integer number (526002048).

Almost surely, 2^2056189781 is an apocalyptic number.

It is an amenable number.

2056189781 is a deficient number, since it is larger than the sum of its proper divisors (47818411).

2056189781 is an equidigital number, since it uses as much as digits as its factorization.

2056189781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47818410.

The product of its (nonzero) digits is 241920, while the sum is 47.

The square root of 2056189781 is about 45345.2288669933. The cubic root of 2056189781 is about 1271.6113592973.

The spelling of 2056189781 in words is "two billion, fifty-six million, one hundred eighty-nine thousand, seven hundred eighty-one".