13947821 has 8 divisors (see below), whose sum is σ = 14593344. Its totient is φ = 13305600.

The previous prime is 13947809. The next prime is 13947823. The reversal of 13947821 is 12874931.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 13947821 - 2⁶ = 13947757 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13947823) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12746 + ... + 13796.

It is an arithmetic number, because the mean of its divisors is an integer number (1824168).

Almost surely, 2^13947821 is an apocalyptic number.

It is an amenable number.

13947821 is a deficient number, since it is larger than the sum of its proper divisors (645523).

13947821 is a wasteful number, since it uses less digits than its factorization.

13947821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1651.

The product of its digits is 12096, while the sum is 35.

The square root of 13947821 is about 3734.6781655184. The cubic root of 13947821 is about 240.7144279059.

The spelling of 13947821 in words is "thirteen million, nine hundred forty-seven thousand, eight hundred twenty-one".