16221530 has 16 divisors (see below), whose sum is σ = 31445064. Its totient is φ = 5989440.

The previous prime is 16221529. The next prime is 16221563. The reversal of 16221530 is 3512261.

It can be written as a sum of positive squares in 4 ways, for example, as 11082241 + 5139289 = 3329^2 + 2267^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 62261 + ... + 62520.

Almost surely, 2^16221530 is an apocalyptic number.

16221530 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

16221530 is a deficient number, since it is larger than the sum of its proper divisors (15223534).

16221530 is a wasteful number, since it uses less digits than its factorization.

16221530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124801.

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 16221530 is about 4027.5960572034. The cubic root of 16221530 is about 253.1418432119.

Adding to 16221530 its reverse (3512261), we get a palindrome (19733791).

The spelling of 16221530 in words is "sixteen million, two hundred twenty-one thousand, five hundred thirty".