21616153 has 4 divisors (see below), whose sum is σ = 23278948. Its totient is φ = 19953360.

The previous prime is 21616141. The next prime is 21616157. The reversal of 21616153 is 35161612.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 10942864 + 10673289 = 3308^2 + 3267^2 .

It is a cyclic number.

It is not a de Polignac number, because 21616153 - 2⁹ = 21615641 is a prime.

It is a Duffinian number.

It is a plaindrome in base 11.

It is not an unprimeable number, because it can be changed into a prime (21616157) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 831378 + ... + 831403.

It is an arithmetic number, because the mean of its divisors is an integer number (5819737).

Almost surely, 2^21616153 is an apocalyptic number.

It is an amenable number.

21616153 is a deficient number, since it is larger than the sum of its proper divisors (1662795).

21616153 is a wasteful number, since it uses less digits than its factorization.

21616153 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1662794.

The product of its digits is 1080, while the sum is 25.

The square root of 21616153 is about 4649.3174767916. The cubic root of 21616153 is about 278.5647345563.

Adding to 21616153 its reverse (35161612), we get a palindrome (56777765).

The spelling of 21616153 in words is "twenty-one million, six hundred sixteen thousand, one hundred fifty-three".