16051621 has 8 divisors (see below), whose sum is σ = 17112600. Its totient is φ = 15003648.

The previous prime is 16051597. The next prime is 16051649. The reversal of 16051621 is 12615061.

It can be written as a sum of positive squares in 4 ways, for example, as 950625 + 15100996 = 975^2 + 3886^2 .

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 16051621 - 2⁵ = 16051589 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 16051592 and 16051601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16051661) 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, 636 + ... + 5701.

It is an arithmetic number, because the mean of its divisors is an integer number (2139075).

Almost surely, 2^16051621 is an apocalyptic number.

It is an amenable number.

16051621 is a deficient number, since it is larger than the sum of its proper divisors (1060979).

16051621 is a wasteful number, since it uses less digits than its factorization.

16051621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6503.

The product of its (nonzero) digits is 360, while the sum is 22.

The square root of 16051621 is about 4006.4474288327. The cubic root of 16051621 is about 252.2549123327.

Adding to 16051621 its reverse (12615061), we get a palindrome (28666682).

The spelling of 16051621 in words is "sixteen million, fifty-one thousand, six hundred twenty-one".