21653045 has 8 divisors (see below), whose sum is σ = 26013624. Its totient is φ = 17302464.

The previous prime is 21653039. The next prime is 21653057. The reversal of 21653045 is 54035612.

It can be written as a sum of positive squares in 4 ways, for example, as 188356 + 21464689 = 434^2 + 4633^2 .

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 21653045 - 2⁸ = 21652789 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3647 + ... + 7523.

It is an arithmetic number, because the mean of its divisors is an integer number (3251703).

Almost surely, 2^21653045 is an apocalyptic number.

It is an amenable number.

21653045 is a deficient number, since it is larger than the sum of its proper divisors (4360579).

21653045 is a wasteful number, since it uses less digits than its factorization.

21653045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4999.

The product of its (nonzero) digits is 3600, while the sum is 26.

The square root of 21653045 is about 4653.2832494917. The cubic root of 21653045 is about 278.7231187253.

Adding to 21653045 its reverse (54035612), we get a palindrome (75688657).

The spelling of 21653045 in words is "twenty-one million, six hundred fifty-three thousand, forty-five".