21725065 has 8 divisors (see below), whose sum is σ = 27603720. Its totient is φ = 16357632.

The previous prime is 21725063. The next prime is 21725101. The reversal of 21725065 is 56052712.

It can be written as a sum of positive squares in 4 ways, for example, as 491401 + 21233664 = 701^2 + 4608^2 .

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 21725065 - 2¹ = 21725063 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21725063) 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, 127710 + ... + 127879.

It is an arithmetic number, because the mean of its divisors is an integer number (3450465).

Almost surely, 2^21725065 is an apocalyptic number.

It is an amenable number.

21725065 is a deficient number, since it is larger than the sum of its proper divisors (5878655).

21725065 is a wasteful number, since it uses less digits than its factorization.

21725065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 255611.

The product of its (nonzero) digits is 4200, while the sum is 28.

The square root of 21725065 is about 4661.0154473033. The cubic root of 21725065 is about 279.0317962417.

Adding to 21725065 its reverse (56052712), we get a palindrome (77777777).

The spelling of 21725065 in words is "twenty-one million, seven hundred twenty-five thousand, sixty-five".