21272372 has 24 divisors (see below), whose sum is σ = 43001280. Its totient is φ = 9100160.

The previous prime is 21272371. The next prime is 21272411. The reversal of 21272372 is 27327212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21272371) 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, 13472 + ... + 14967.

It is an arithmetic number, because the mean of its divisors is an integer number (1791720).

Almost surely, 2^21272372 is an apocalyptic number.

21272372 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21272372 is an abundant number, since it is smaller than the sum of its proper divisors (21728908).

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

21272372 is a wasteful number, since it uses less digits than its factorization.

21272372 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28471 (or 28469 counting only the distinct ones).

The product of its digits is 2352, while the sum is 26.

The square root of 21272372 is about 4612.1981744066. The cubic root of 21272372 is about 277.0800812829.

Adding to 21272372 its reverse (27327212), we get a palindrome (48599584).

The spelling of 21272372 in words is "twenty-one million, two hundred seventy-two thousand, three hundred seventy-two".