13921247 has 4 divisors (see below), whose sum is σ = 14401320. Its totient is φ = 13441176.

The previous prime is 13921241. The next prime is 13921289. The reversal of 13921247 is 74212931.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 74212931 = 13 ⋅5708687.

It is a cyclic number.

It is not a de Polignac number, because 13921247 - 2⁴ = 13921231 is a prime.

It is a super-2 number, since 2×13921247² = 387602236070018, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (29), and also a Moran number because the ratio is a prime number: 480043 = 13921247 / (1 + 3 + 9 + 2 + 1 + 2 + 4 + 7).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13921241) 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, 239993 + ... + 240050.

It is an arithmetic number, because the mean of its divisors is an integer number (3600330).

Almost surely, 2^13921247 is an apocalyptic number.

13921247 is a deficient number, since it is larger than the sum of its proper divisors (480073).

13921247 is an equidigital number, since it uses as much as digits as its factorization.

13921247 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 480072.

The product of its digits is 3024, while the sum is 29.

The square root of 13921247 is about 3731.1187330344. The cubic root of 13921247 is about 240.5614574894.

The spelling of 13921247 in words is "thirteen million, nine hundred twenty-one thousand, two hundred forty-seven".