21027725 has 12 divisors (see below), whose sum is σ = 27608724. Its totient is φ = 15832320.

The previous prime is 21027709. The next prime is 21027767. The reversal of 21027725 is 52772012.

It can be written as a sum of positive squares in 6 ways, for example, as 407044 + 20620681 = 638^2 + 4541^2 .

It is not a de Polignac number, because 21027725 - 2⁴ = 21027709 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21027694 and 21027703.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 24314 + ... + 25163.

It is an arithmetic number, because the mean of its divisors is an integer number (2300727).

Almost surely, 2^21027725 is an apocalyptic number.

21027725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21027725 is a deficient number, since it is larger than the sum of its proper divisors (6580999).

21027725 is a wasteful number, since it uses less digits than its factorization.

21027725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49504 (or 49499 counting only the distinct ones).

The product of its (nonzero) digits is 1960, while the sum is 26.

The square root of 21027725 is about 4585.5997426727. The cubic root of 21027725 is about 276.0137788052.

Adding to 21027725 its reverse (52772012), we get a palindrome (73799737).

The spelling of 21027725 in words is "twenty-one million, twenty-seven thousand, seven hundred twenty-five".