21616154 has 12 divisors (see below), whose sum is σ = 37718154. Its totient is φ = 9264024.

The previous prime is 21616141. The next prime is 21616157. The reversal of 21616154 is 45161612.

It can be written as a sum of positive squares in only one way, i.e., 21409129 + 207025 = 4627^2 + 455^2 .

It is a super-2 number, since 2×21616154² = 934516227503432, which contains 22 as substring.

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 5 ways as a sum of consecutive naturals, for example, 110189 + ... + 110384.

Almost surely, 2^21616154 is an apocalyptic number.

21616154 is a deficient number, since it is larger than the sum of its proper divisors (16102000).

21616154 is a wasteful number, since it uses less digits than its factorization.

21616154 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 220589 (or 220582 counting only the distinct ones).

The product of its digits is 1440, while the sum is 26.

The square root of 21616154 is about 4649.3175843343. The cubic root of 21616154 is about 278.5647388519.

Adding to 21616154 its reverse (45161612), we get a palindrome (66777766).

The spelling of 21616154 in words is "twenty-one million, six hundred sixteen thousand, one hundred fifty-four".