21694272 has 56 divisors (see below), whose sum is σ = 58009536. Its totient is φ = 7154688.

The previous prime is 21694271. The next prime is 21694273. The reversal of 21694272 is 27249612.

It is an interprime number because it is at equal distance from previous prime (21694271) and next prime (21694273).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21694271) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19228 + ... + 20324.

Almost surely, 2^21694272 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21694272, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29004768).

21694272 is an abundant number, since it is smaller than the sum of its proper divisors (36315264).

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

21694272 is a wasteful number, since it uses less digits than its factorization.

21694272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1215 (or 1205 counting only the distinct ones).

The product of its digits is 12096, while the sum is 33.

The square root of 21694272 is about 4657.7110258151. The cubic root of 21694272 is about 278.8999011423.

It can be divided in two parts, 2169 and 4272, that added together give a triangular number (6441 = T₁₁₃).

The spelling of 21694272 in words is "twenty-one million, six hundred ninety-four thousand, two hundred seventy-two".