21625065 has 72 divisors (see below), whose sum is σ = 47331648. Its totient is φ = 8873280.

The previous prime is 21625063. The next prime is 21625067. The reversal of 21625065 is 56052612.

It is an interprime number because it is at equal distance from previous prime (21625063) and next prime (21625067).

It is not a de Polignac number, because 21625065 - 2¹ = 21625063 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21625061) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 273696 + ... + 273774.

It is an arithmetic number, because the mean of its divisors is an integer number (657384).

Almost surely, 2^21625065 is an apocalyptic number.

It is an amenable number.

21625065 is an abundant number, since it is smaller than the sum of its proper divisors (25706583).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21625065 is a wasteful number, since it uses less digits than its factorization.

21625065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 187 (or 105 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 21625065 is about 4650.2757982726. The cubic root of 21625065 is about 278.6030119164.

Adding to 21625065 its reverse (56052612), we get a palindrome (77677677).

It can be divided in two parts, 2162 and 5065, that added together give a palindrome (7227).

The spelling of 21625065 in words is "twenty-one million, six hundred twenty-five thousand, sixty-five".