21052645 has 8 divisors (see below), whose sum is σ = 25288704. Its totient is φ = 16825104.

The previous prime is 21052643. The next prime is 21052651. The reversal of 21052645 is 54625012.

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 21052645 - 2¹ = 21052643 is a prime.

It is a super-2 number, since 2×21052645² = 886427722992050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21052643) 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, 6492 + ... + 9178.

It is an arithmetic number, because the mean of its divisors is an integer number (3161088).

Almost surely, 2^21052645 is an apocalyptic number.

It is an amenable number.

21052645 is a deficient number, since it is larger than the sum of its proper divisors (4236059).

21052645 is a wasteful number, since it uses less digits than its factorization.

21052645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4259.

The product of its (nonzero) digits is 2400, while the sum is 25.

The square root of 21052645 is about 4588.3161399363. The cubic root of 21052645 is about 276.1227705928.

Adding to 21052645 its reverse (54625012), we get a palindrome (75677657).

The spelling of 21052645 in words is "twenty-one million, fifty-two thousand, six hundred forty-five".