99891947 has 2 divisors, whose sum is σ = 99891948. Its totient is φ = 99891946.

The previous prime is 99891923. The next prime is 99891989. The reversal of 99891947 is 74919899.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 99891947 - 2¹⁶ = 99826411 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 99891892 and 99891901.

It is not a weakly prime, because it can be changed into another prime (99891917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49945973 + 49945974.

It is an arithmetic number, because the mean of its divisors is an integer number (49945974).

Almost surely, 2^99891947 is an apocalyptic number.

99891947 is a deficient number, since it is larger than the sum of its proper divisors (1).

99891947 is an equidigital number, since it uses as much as digits as its factorization.

99891947 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1469664, while the sum is 56.

The square root of 99891947 is about 9994.5958897796. The cubic root of 99891947 is about 463.9916439116.

The spelling of 99891947 in words is "ninety-nine million, eight hundred ninety-one thousand, nine hundred forty-seven".