21445653 has 8 divisors (see below), whose sum is σ = 30276288. Its totient is φ = 13456064.

The previous prime is 21445651. The next prime is 21445657. The reversal of 21445653 is 35654412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21445653 - 2¹ = 21445651 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21445653.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21445651) 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, 210201 + ... + 210302.

It is an arithmetic number, because the mean of its divisors is an integer number (3784536).

Almost surely, 2^21445653 is an apocalyptic number.

It is an amenable number.

21445653 is a deficient number, since it is larger than the sum of its proper divisors (8830635).

21445653 is a wasteful number, since it uses less digits than its factorization.

21445653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 420523.

The product of its digits is 14400, while the sum is 30.

The square root of 21445653 is about 4630.9451519101. The cubic root of 21445653 is about 277.8303961773.

The spelling of 21445653 in words is "twenty-one million, four hundred forty-five thousand, six hundred fifty-three".