1891954487 has 2 divisors, whose sum is σ = 1891954488. Its totient is φ = 1891954486.

The previous prime is 1891954481. The next prime is 1891954513. The reversal of 1891954487 is 7844591981.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1891954487 - 2⁶ = 1891954423 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1891954481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 945977243 + 945977244.

It is an arithmetic number, because the mean of its divisors is an integer number (945977244).

Almost surely, 2^1891954487 is an apocalyptic number.

1891954487 is a deficient number, since it is larger than the sum of its proper divisors (1).

1891954487 is an equidigital number, since it uses as much as digits as its factorization.

1891954487 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2903040, while the sum is 56.

The square root of 1891954487 is about 43496.6031662244. The cubic root of 1891954487 is about 1236.8116335153.

The spelling of 1891954487 in words is "one billion, eight hundred ninety-one million, nine hundred fifty-four thousand, four hundred eighty-seven".