21355272 has 32 divisors (see below), whose sum is σ = 59320800. Its totient is φ = 7118352.

The previous prime is 21355267. The next prime is 21355273. The reversal of 21355272 is 27255312.

21355272 is a `hidden beast` number, since 2 + 135 + 527 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21355273) 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, 49218 + ... + 49649.

It is an arithmetic number, because the mean of its divisors is an integer number (1853775).

Almost surely, 2^21355272 is an apocalyptic number.

It is an amenable number.

21355272 is an abundant number, since it is smaller than the sum of its proper divisors (37965528).

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

21355272 is a wasteful number, since it uses less digits than its factorization.

21355272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98882 (or 98872 counting only the distinct ones).

The product of its digits is 4200, while the sum is 27.

The square root of 21355272 is about 4621.1764735833. The cubic root of 21355272 is about 277.4395485559.

The spelling of 21355272 in words is "twenty-one million, three hundred fifty-five thousand, two hundred seventy-two".