10647991 has 4 divisors (see below), whose sum is σ = 10874592. Its totient is φ = 10421392.

The previous prime is 10647983. The next prime is 10648021. The reversal of 10647991 is 19974601.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19974601 = 2203 ⋅9067.

It is a cyclic number.

It is not a de Polignac number, because 10647991 - 2³ = 10647983 is a prime.

It is a super-2 number, since 2×10647991² = 226759424672162, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 10647991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10647191) 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, 113230 + ... + 113323.

It is an arithmetic number, because the mean of its divisors is an integer number (2718648).

Almost surely, 2^10647991 is an apocalyptic number.

10647991 is a deficient number, since it is larger than the sum of its proper divisors (226601).

10647991 is an equidigital number, since it uses as much as digits as its factorization.

10647991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 226600.

The product of its (nonzero) digits is 13608, while the sum is 37.

The square root of 10647991 is about 3263.1259552766. The cubic root of 10647991 is about 219.9999380165. Note that the first 4 decimals are identical.

The spelling of 10647991 in words is "ten million, six hundred forty-seven thousand, nine hundred ninety-one".