15481221 has 16 divisors (see below), whose sum is σ = 23944704. Its totient is φ = 8713584.

The previous prime is 15481217. The next prime is 15481223. The reversal of 15481221 is 12218451.

15481221 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 15481221 - 2² = 15481217 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 15481191 and 15481200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15481223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4095 + ... + 6908.

It is an arithmetic number, because the mean of its divisors is an integer number (1496544).

Almost surely, 2^15481221 is an apocalyptic number.

It is an amenable number.

15481221 is a deficient number, since it is larger than the sum of its proper divisors (8463483).

15481221 is a wasteful number, since it uses less digits than its factorization.

15481221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11080.

The product of its digits is 640, while the sum is 24.

The square root of 15481221 is about 3934.6182788169. The cubic root of 15481221 is about 249.2308145085.

Adding to 15481221 its reverse (12218451), we get a palindrome (27699672).

The spelling of 15481221 in words is "fifteen million, four hundred eighty-one thousand, two hundred twenty-one".