13987221 has 8 divisors (see below), whose sum is σ = 19153824. Its totient is φ = 9072720.

The previous prime is 13987219. The next prime is 13987241. The reversal of 13987221 is 12278931.

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

It is not a de Polignac number, because 13987221 - 2¹ = 13987219 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13987241) 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, 62895 + ... + 63116.

It is an arithmetic number, because the mean of its divisors is an integer number (2394228).

Almost surely, 2^13987221 is an apocalyptic number.

It is an amenable number.

13987221 is a deficient number, since it is larger than the sum of its proper divisors (5166603).

13987221 is a wasteful number, since it uses less digits than its factorization.

13987221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126051.

The product of its digits is 6048, while the sum is 33.

The square root of 13987221 is about 3739.9493312076. The cubic root of 13987221 is about 240.9408726466.

The spelling of 13987221 in words is "thirteen million, nine hundred eighty-seven thousand, two hundred twenty-one".