21069188 has 24 divisors (see below), whose sum is σ = 44618112. Its totient is φ = 8498304.

The previous prime is 21069163. The next prime is 21069199. The reversal of 21069188 is 88196012.

It is an unprimeable number.

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, 21656 + ... + 22607.

It is an arithmetic number, because the mean of its divisors is an integer number (1859088).

Almost surely, 2^21069188 is an apocalyptic number.

21069188 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21069188 is an abundant number, since it is smaller than the sum of its proper divisors (23548924).

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

21069188 is a wasteful number, since it uses less digits than its factorization.

21069188 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44291 (or 44289 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 35.

The square root of 21069188 is about 4590.1185169884. The cubic root of 21069188 is about 276.1950766782.

The spelling of 21069188 in words is "twenty-one million, sixty-nine thousand, one hundred eighty-eight".