25821011 has 4 divisors (see below), whose sum is σ = 27339912. Its totient is φ = 24302112.

The previous prime is 25820989. The next prime is 25821043. The reversal of 25821011 is 11012852.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a de Polignac number, because none of the positive numbers 2^k-25821011 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25821091) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 759425 + ... + 759458.

It is an arithmetic number, because the mean of its divisors is an integer number (6834978).

Almost surely, 2^25821011 is an apocalyptic number.

25821011 is a deficient number, since it is larger than the sum of its proper divisors (1518901).

25821011 is a wasteful number, since it uses less digits than its factorization.

25821011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1518900.

The product of its (nonzero) digits is 160, while the sum is 20.

The square root of 25821011 is about 5081.4378870552. The cubic root of 25821011 is about 295.5682277708.

Adding to 25821011 its reverse (11012852), we get a palindrome (36833863).

The spelling of 25821011 in words is "twenty-five million, eight hundred twenty-one thousand, eleven".