21652345 has 24 divisors (see below), whose sum is σ = 30767688. Its totient is φ = 14530560.

The previous prime is 21652331. The next prime is 21652391. The reversal of 21652345 is 54325612.

It can be written as a sum of positive squares in 4 ways, for example, as 3059001 + 18593344 = 1749^2 + 4312^2 .

It is not a de Polignac number, because 21652345 - 2⁷ = 21652217 is a prime.

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6489 + ... + 9241.

It is an arithmetic number, because the mean of its divisors is an integer number (1281987).

Almost surely, 2^21652345 is an apocalyptic number.

It is an amenable number.

21652345 is a deficient number, since it is larger than the sum of its proper divisors (9115343).

21652345 is a wasteful number, since it uses less digits than its factorization.

21652345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2793 (or 2782 counting only the distinct ones).

The product of its digits is 7200, while the sum is 28.

The square root of 21652345 is about 4653.2080331745. The cubic root of 21652345 is about 278.7201151711.

Adding to 21652345 its reverse (54325612), we get a palindrome (75977957).

The spelling of 21652345 in words is "twenty-one million, six hundred fifty-two thousand, three hundred forty-five".