21115154 has 16 divisors (see below), whose sum is σ = 33040896. Its totient is φ = 10108800.

The previous prime is 21115141. The next prime is 21115189. The reversal of 21115154 is 45151112.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4259 + ... + 7769.

It is an arithmetic number, because the mean of its divisors is an integer number (2065056).

Almost surely, 2^21115154 is an apocalyptic number.

21115154 is a deficient number, since it is larger than the sum of its proper divisors (11925742).

21115154 is a wasteful number, since it uses less digits than its factorization.

21115154 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3641.

The product of its digits is 200, while the sum is 20.

The square root of 21115154 is about 4595.1228492827. The cubic root of 21115154 is about 276.3957862253.

Adding to 21115154 its reverse (45151112), we get a palindrome (66266266).

The spelling of 21115154 in words is "twenty-one million, one hundred fifteen thousand, one hundred fifty-four".