10399891 has 4 divisors (see below), whose sum is σ = 10407592. Its totient is φ = 10392192.

The previous prime is 10399877. The next prime is 10399901. The reversal of 10399891 is 19899301.

10399891 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-10399891 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (10399811) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1230 + ... + 4723.

It is an arithmetic number, because the mean of its divisors is an integer number (2601898).

Almost surely, 2^10399891 is an apocalyptic number.

10399891 is a deficient number, since it is larger than the sum of its proper divisors (7701).

10399891 is an equidigital number, since it uses as much as digits as its factorization.

10399891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7700.

The product of its (nonzero) digits is 17496, while the sum is 40.

The square root of 10399891 is about 3224.8861995426. The cubic root of 10399891 is about 218.2778140338.

The spelling of 10399891 in words is "ten million, three hundred ninety-nine thousand, eight hundred ninety-one".