25821031 has 4 divisors (see below), whose sum is σ = 25838272. Its totient is φ = 25803792.

The previous prime is 25820989. The next prime is 25821043. The reversal of 25821031 is 13012852.

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

It is a cyclic number.

It is not a de Polignac number, because 25821031 - 2¹⁷ = 25689959 is a prime.

It is a super-2 number, since 2×25821031² = 1333451283805922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 25820993 and 25821011.

It is a congruent number.

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

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6135 + ... + 9448.

It is an arithmetic number, because the mean of its divisors is an integer number (6459568).

Almost surely, 2^25821031 is an apocalyptic number.

25821031 is a deficient number, since it is larger than the sum of its proper divisors (17241).

25821031 is a wasteful number, since it uses less digits than its factorization.

25821031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17240.

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 25821031 is about 5081.4398550017. The cubic root of 25821031 is about 295.5683040828.

Adding to 25821031 its reverse (13012852), we get a palindrome (38833883).

The spelling of 25821031 in words is "twenty-five million, eight hundred twenty-one thousand, thirty-one".