21699212 has 24 divisors (see below), whose sum is σ = 39895296. Its totient is φ = 10307088.

The previous prime is 21699211. The next prime is 21699229. The reversal of 21699212 is 21299612.

It is not an unprimeable number, because it can be changed into a prime (21699211) 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, 14273 + ... + 15719.

It is an arithmetic number, because the mean of its divisors is an integer number (1662304).

Almost surely, 2^21699212 is an apocalyptic number.

It is an amenable number.

21699212 is a deficient number, since it is larger than the sum of its proper divisors (18196084).

21699212 is a wasteful number, since it uses less digits than its factorization.

21699212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1637 (or 1635 counting only the distinct ones).

The product of its digits is 3888, while the sum is 32.

The square root of 21699212 is about 4658.2412990312. The cubic root of 21699212 is about 278.9210689563.

The spelling of 21699212 in words is "twenty-one million, six hundred ninety-nine thousand, two hundred twelve".