16021621 has 8 divisors (see below), whose sum is σ = 19975104. Its totient is φ = 12484320.

The previous prime is 16021613. The next prime is 16021651. The reversal of 16021621 is 12612061.

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

It is a cyclic number.

It is not a de Polignac number, because 16021621 - 2³ = 16021613 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16021651) 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, 103960 + ... + 104113.

It is an arithmetic number, because the mean of its divisors is an integer number (2496888).

Almost surely, 2^16021621 is an apocalyptic number.

16021621 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

16021621 is a deficient number, since it is larger than the sum of its proper divisors (3953483).

16021621 is a wasteful number, since it uses less digits than its factorization.

16021621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 208091.

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 16021621 is about 4002.7017125936. The cubic root of 16021621 is about 252.0976620288.

Adding to 16021621 its reverse (12612061), we get a palindrome (28633682).

It can be divided in two parts, 1602 and 1621, that added together give a palindrome (3223).

The spelling of 16021621 in words is "sixteen million, twenty-one thousand, six hundred twenty-one".