1890681161 has 2 divisors, whose sum is σ = 1890681162. Its totient is φ = 1890681160.

The previous prime is 1890681139. The next prime is 1890681217. The reversal of 1890681161 is 1611860981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1612825600 + 277855561 = 40160^2 + 16669^2 .

It is an emirp because it is prime and its reverse (1611860981) is a distict prime. It is also a bemirp because it and its reverse can be mirrored producing other two distinct primes, 1911890681 and 1860981191.

It is a cyclic number.

It is not a de Polignac number, because 1890681161 - 2¹⁴ = 1890664777 is a prime.

It is not a weakly prime, because it can be changed into another prime (1890683161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 945340580 + 945340581.

It is an arithmetic number, because the mean of its divisors is an integer number (945340581).

Almost surely, 2^1890681161 is an apocalyptic number.

It is an amenable number.

1890681161 is a deficient number, since it is larger than the sum of its proper divisors (1).

1890681161 is an equidigital number, since it uses as much as digits as its factorization.

1890681161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20736, while the sum is 41.

The square root of 1890681161 is about 43481.9636286127. The cubic root of 1890681161 is about 1236.5341043148.

The spelling of 1890681161 in words is "one billion, eight hundred ninety million, six hundred eighty-one thousand, one hundred sixty-one".