1891094657 has 2 divisors, whose sum is σ = 1891094658. Its totient is φ = 1891094656.

The previous prime is 1891094641. The next prime is 1891094683. The reversal of 1891094657 is 7564901981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1551650881 + 339443776 = 39391^2 + 18424^2 .

It is a cyclic number.

It is not a de Polignac number, because 1891094657 - 2⁴ = 1891094641 is a prime.

It is not a weakly prime, because it can be changed into another prime (1891094627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 945547328 + 945547329.

It is an arithmetic number, because the mean of its divisors is an integer number (945547329).

Almost surely, 2^1891094657 is an apocalyptic number.

It is an amenable number.

1891094657 is a deficient number, since it is larger than the sum of its proper divisors (1).

1891094657 is an equidigital number, since it uses as much as digits as its factorization.

1891094657 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 544320, while the sum is 50.

The square root of 1891094657 is about 43486.7181677348. The cubic root of 1891094657 is about 1236.6242419588.

The spelling of 1891094657 in words is "one billion, eight hundred ninety-one million, ninety-four thousand, six hundred fifty-seven".