16293991 has 4 divisors (see below), whose sum is σ = 18621712. Its totient is φ = 13966272.

The previous prime is 16293989. The next prime is 16294009. The reversal of 16293991 is 19939261.

16293991 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, and also an emirpimes, since its reverse is a distinct semiprime: 19939261 = 109 ⋅182929.

It is a cyclic number.

It is not a de Polignac number, because 16293991 - 2¹ = 16293989 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 (16293961) 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, 1163850 + ... + 1163863.

It is an arithmetic number, because the mean of its divisors is an integer number (4655428).

Almost surely, 2^16293991 is an apocalyptic number.

16293991 is a deficient number, since it is larger than the sum of its proper divisors (2327721).

16293991 is an equidigital number, since it uses as much as digits as its factorization.

16293991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2327720.

The product of its digits is 26244, while the sum is 40.

The square root of 16293991 is about 4036.5815983329. The cubic root of 16293991 is about 253.5182085794.

The spelling of 16293991 in words is "sixteen million, two hundred ninety-three thousand, nine hundred ninety-one".