21502116 has 36 divisors (see below), whose sum is σ = 54792192. Its totient is φ = 7109424.

The previous prime is 21502111. The next prime is 21502123. The reversal of 21502116 is 61120512.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21502111) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2221 + ... + 6923.

Almost surely, 2^21502116 is an apocalyptic number.

It is an amenable number.

21502116 is an abundant number, since it is smaller than the sum of its proper divisors (33290076).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21502116 is a wasteful number, since it uses less digits than its factorization.

21502116 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4840 (or 4835 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

The square root of 21502116 is about 4637.0374162821. The cubic root of 21502116 is about 278.0740102796.

Adding to 21502116 its reverse (61120512), we get a palindrome (82622628).

The spelling of 21502116 in words is "twenty-one million, five hundred two thousand, one hundred sixteen".