21427653 has 16 divisors (see below), whose sum is σ = 31275776. Its totient is φ = 12968640.

The previous prime is 21427643. The next prime is 21427657. The reversal of 21427653 is 35672412.

It is not a de Polignac number, because 21427653 - 2⁵ = 21427621 is a prime.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21427653.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21427657) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2125 + ... + 6882.

It is an arithmetic number, because the mean of its divisors is an integer number (1954736).

Almost surely, 2^21427653 is an apocalyptic number.

It is an amenable number.

21427653 is a deficient number, since it is larger than the sum of its proper divisors (9848123).

21427653 is a wasteful number, since it uses less digits than its factorization.

21427653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9084.

The product of its digits is 10080, while the sum is 30.

The square root of 21427653 is about 4629.0012961761. The cubic root of 21427653 is about 277.7526438711.

The spelling of 21427653 in words is "twenty-one million, four hundred twenty-seven thousand, six hundred fifty-three".