1891000949 has 2 divisors, whose sum is σ = 1891000950. Its totient is φ = 1891000948.

The previous prime is 1891000931. The next prime is 1891000963. The reversal of 1891000949 is 9490001981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1583244100 + 307756849 = 39790^2 + 17543^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1891000949 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1891020949) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 945500474 + 945500475.

It is an arithmetic number, because the mean of its divisors is an integer number (945500475).

Almost surely, 2^1891000949 is an apocalyptic number.

It is an amenable number.

1891000949 is a deficient number, since it is larger than the sum of its proper divisors (1).

1891000949 is an equidigital number, since it uses as much as digits as its factorization.

1891000949 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23328, while the sum is 41.

The square root of 1891000949 is about 43485.6407219671. The cubic root of 1891000949 is about 1236.6038157825.

The spelling of 1891000949 in words is "one billion, eight hundred ninety-one million, nine hundred forty-nine", and thus it is an aban number.