15748991 has 4 divisors (see below), whose sum is σ = 15836184. Its totient is φ = 15661800.

The previous prime is 15748981. The next prime is 15749011. The reversal of 15748991 is 19984751.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19984751 = 19 ⋅1051829.

It is a cyclic number.

It is not a de Polignac number, because 15748991 - 2⁶ = 15748927 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 (15748921) 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, 43325 + ... + 43686.

It is an arithmetic number, because the mean of its divisors is an integer number (3959046).

Almost surely, 2^15748991 is an apocalyptic number.

15748991 is a deficient number, since it is larger than the sum of its proper divisors (87193).

15748991 is an equidigital number, since it uses as much as digits as its factorization.

15748991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87192.

The product of its digits is 90720, while the sum is 44.

The square root of 15748991 is about 3968.4998425098. The cubic root of 15748991 is about 250.6595438110.

The spelling of 15748991 in words is "fifteen million, seven hundred forty-eight thousand, nine hundred ninety-one".