11403991 has 4 divisors (see below), whose sum is σ = 12074832. Its totient is φ = 10733152.

The previous prime is 11403967. The next prime is 11404007. The reversal of 11403991 is 19930411.

It is a happy number.

11403991 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 11403991 - 2⁹ = 11403479 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11403941) 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, 335395 + ... + 335428.

It is an arithmetic number, because the mean of its divisors is an integer number (3018708).

Almost surely, 2^11403991 is an apocalyptic number.

11403991 is a deficient number, since it is larger than the sum of its proper divisors (670841).

11403991 is an equidigital number, since it uses as much as digits as its factorization.

11403991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 670840.

The product of its (nonzero) digits is 972, while the sum is 28.

The square root of 11403991 is about 3376.9795676018. The cubic root of 11403991 is about 225.0879721839.

The spelling of 11403991 in words is "eleven million, four hundred three thousand, nine hundred ninety-one".