21772236 has 24 divisors (see below), whose sum is σ = 51118144. Its totient is φ = 7212240.

The previous prime is 21772229. The next prime is 21772259. The reversal of 21772236 is 63227712.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3610 + ... + 7521.

Almost surely, 2^21772236 is an apocalyptic number.

It is an amenable number.

21772236 is an abundant number, since it is smaller than the sum of its proper divisors (29345908).

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

21772236 is a wasteful number, since it uses less digits than its factorization.

21772236 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11301 (or 11299 counting only the distinct ones).

The product of its digits is 7056, while the sum is 30.

The square root of 21772236 is about 4666.0728669835. The cubic root of 21772236 is about 279.2336014545.

Adding to 21772236 its reverse (63227712), we get a palindrome (84999948).

The spelling of 21772236 in words is "twenty-one million, seven hundred seventy-two thousand, two hundred thirty-six".