891987563 has 2 divisors, whose sum is σ = 891987564. Its totient is φ = 891987562.

The previous prime is 891987559. The next prime is 891987589. The reversal of 891987563 is 365789198.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 891987563 - 2² = 891987559 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 891987499 and 891987508.

It is not a weakly prime, because it can be changed into another prime (891987533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 445993781 + 445993782.

It is an arithmetic number, because the mean of its divisors is an integer number (445993782).

Almost surely, 2^891987563 is an apocalyptic number.

891987563 is a deficient number, since it is larger than the sum of its proper divisors (1).

891987563 is an equidigital number, since it uses as much as digits as its factorization.

891987563 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3265920, while the sum is 56.

The square root of 891987563 is about 29866.1608346302. The cubic root of 891987563 is about 962.6156831326.

The spelling of 891987563 in words is "eight hundred ninety-one million, nine hundred eighty-seven thousand, five hundred sixty-three".