25005721 has 8 divisors (see below), whose sum is σ = 26977160. Its totient is φ = 23041152.

The previous prime is 25005713. The next prime is 25005731. The reversal of 25005721 is 12750052.

It can be written as a sum of positive squares in 4 ways, for example, as 2576025 + 22429696 = 1605^2 + 4736^2 .

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 25005721 - 2³ = 25005713 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 25005692 and 25005701.

It is not an unprimeable number, because it can be changed into a prime (25005731) 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, 7861 + ... + 10573.

It is an arithmetic number, because the mean of its divisors is an integer number (3372145).

Almost surely, 2^25005721 is an apocalyptic number.

It is an amenable number.

25005721 is a deficient number, since it is larger than the sum of its proper divisors (1971439).

25005721 is a wasteful number, since it uses less digits than its factorization.

25005721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3435.

The product of its (nonzero) digits is 700, while the sum is 22.

The square root of 25005721 is about 5000.5720672739. The cubic root of 25005721 is about 292.4240765274.

Adding to 25005721 its reverse (12750052), we get a palindrome (37755773).

The spelling of 25005721 in words is "twenty-five million, five thousand, seven hundred twenty-one".