21216150 has 36 divisors (see below), whose sum is σ = 57001932. Its totient is φ = 5657520.

The previous prime is 21216137. The next prime is 21216191. The reversal of 21216150 is 5161212.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 23124 + ... + 24023.

It is an arithmetic number, because the mean of its divisors is an integer number (1583387).

Almost surely, 2^21216150 is an apocalyptic number.

21216150 is an abundant number, since it is smaller than the sum of its proper divisors (35785782).

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

21216150 is a wasteful number, since it uses less digits than its factorization.

21216150 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47165 (or 47157 counting only the distinct ones).

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

The square root of 21216150 is about 4606.0992173422. The cubic root of 21216150 is about 276.8357621802.

Adding to 21216150 its reverse (5161212), we get a palindrome (26377362).

The spelling of 21216150 in words is "twenty-one million, two hundred sixteen thousand, one hundred fifty".