16221660 has 96 divisors (see below), whose sum is σ = 55921152. Its totient is φ = 3421440.

The previous prime is 16221659. The next prime is 16221661. The reversal of 16221660 is 6612261.

It is an interprime number because it is at equal distance from previous prime (16221659) and next prime (16221661).

It is a self number, because there is not a number n which added to its sum of digits gives 16221660.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16221661) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3975 + ... + 6945.

It is an arithmetic number, because the mean of its divisors is an integer number (582512).

Almost surely, 2^16221660 is an apocalyptic number.

16221660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 16221660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27960576).

16221660 is an abundant number, since it is smaller than the sum of its proper divisors (39699492).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

16221660 is a wasteful number, since it uses less digits than its factorization.

16221660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3003 (or 3001 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 16221660 is about 4027.6121958302. The cubic root of 16221660 is about 253.1425194397.

The spelling of 16221660 in words is "sixteen million, two hundred twenty-one thousand, six hundred sixty".