21155116 has 24 divisors (see below), whose sum is σ = 37861040. Its totient is φ = 10340352.

The previous prime is 21155107. The next prime is 21155117. The reversal of 21155116 is 61155112.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21155117) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 51520 + ... + 51928.

Almost surely, 2^21155116 is an apocalyptic number.

It is an amenable number.

21155116 is a deficient number, since it is larger than the sum of its proper divisors (16705924).

21155116 is a wasteful number, since it uses less digits than its factorization.

21155116 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 673 (or 671 counting only the distinct ones).

The product of its digits is 300, while the sum is 22.

The square root of 21155116 is about 4599.4690997984. The cubic root of 21155116 is about 276.5700428704.

The spelling of 21155116 in words is "twenty-one million, one hundred fifty-five thousand, one hundred sixteen".