999891401 has 2 divisors, whose sum is σ = 999891402. Its totient is φ = 999891400.

The previous prime is 999891383. The next prime is 999891437. The reversal of 999891401 is 104198999.

999891401 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 768121225 + 231770176 = 27715^2 + 15224^2 .

It is a cyclic number.

It is not a de Polignac number, because 999891401 - 2⁶ = 999891337 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 999891401.

It is not a weakly prime, because it can be changed into another prime (999891901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499945700 + 499945701.

It is an arithmetic number, because the mean of its divisors is an integer number (499945701).

Almost surely, 2^999891401 is an apocalyptic number.

It is an amenable number.

999891401 is a deficient number, since it is larger than the sum of its proper divisors (1).

999891401 is an equidigital number, since it uses as much as digits as its factorization.

999891401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 209952, while the sum is 50.

The square root of 999891401 is about 31621.0594541043. The cubic root of 999891401 is about 999.9637990228.

The spelling of 999891401 in words is "nine hundred ninety-nine million, eight hundred ninety-one thousand, four hundred one".