10400991 has 16 divisors (see below), whose sum is σ = 15323904. Its totient is φ = 6241664.

The previous prime is 10400987. The next prime is 10400993. The reversal of 10400991 is 19900401.

10400991 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 10400991 - 2² = 10400987 is a prime.

It is a super-2 number, since 2×10400991² = 216361227564162, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10400993) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3261 + ... + 5606.

It is an arithmetic number, because the mean of its divisors is an integer number (957744).

Almost surely, 2^10400991 is an apocalyptic number.

10400991 is a deficient number, since it is larger than the sum of its proper divisors (4922913).

10400991 is a wasteful number, since it uses less digits than its factorization.

10400991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8910.

The product of its (nonzero) digits is 324, while the sum is 24.

The square root of 10400991 is about 3225.0567436868. The cubic root of 10400991 is about 218.2855095353.

The spelling of 10400991 in words is "ten million, four hundred thousand, nine hundred ninety-one".