21611629 has 8 divisors (see below), whose sum is σ = 23656472. Its totient is φ = 19621440.

The previous prime is 21611621. The next prime is 21611669. The reversal of 21611629 is 92611612.

It can be written as a sum of positive squares in 4 ways, for example, as 202500 + 21409129 = 450^2 + 4627^2 .

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 21611629 - 2³ = 21611621 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21611597 and 21611606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21611621) 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, 12834 + ... + 14419.

It is an arithmetic number, because the mean of its divisors is an integer number (2957059).

Almost surely, 2^21611629 is an apocalyptic number.

It is an amenable number.

21611629 is a deficient number, since it is larger than the sum of its proper divisors (2044843).

21611629 is a wasteful number, since it uses less digits than its factorization.

21611629 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27327.

The product of its digits is 1296, while the sum is 28.

The square root of 21611629 is about 4648.8309283088. The cubic root of 21611629 is about 278.5452997878.

The spelling of 21611629 in words is "twenty-one million, six hundred eleven thousand, six hundred twenty-nine".