16525221 has 8 divisors (see below), whose sum is σ = 22052544. Its totient is φ = 11007360.

The previous prime is 16525183. The next prime is 16525237. The reversal of 16525221 is 12252561.

It is a happy number.

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

It is not a de Polignac number, because 16525221 - 2⁹ = 16524709 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 16525191 and 16525200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16525291) 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, 4920 + ... + 7566.

It is an arithmetic number, because the mean of its divisors is an integer number (2756568).

Almost surely, 2^16525221 is an apocalyptic number.

It is an amenable number.

16525221 is a deficient number, since it is larger than the sum of its proper divisors (5527323).

16525221 is a wasteful number, since it uses less digits than its factorization.

16525221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4731.

The product of its digits is 1200, while the sum is 24.

The square root of 16525221 is about 4065.1225073791. The cubic root of 16525221 is about 254.7118159202.

Adding to 16525221 its reverse (12252561), we get a palindrome (28777782).

The spelling of 16525221 in words is "sixteen million, five hundred twenty-five thousand, two hundred twenty-one".