25831021 has 2 divisors, whose sum is σ = 25831022. Its totient is φ = 25831020.

The previous prime is 25830949. The next prime is 25831063. The reversal of 25831021 is 12013852.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 24890121 + 940900 = 4989^2 + 970^2 .

It is a cyclic number.

It is not a de Polignac number, because 25831021 - 2¹³ = 25822829 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 25830983 and 25831001.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25835021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12915510 + 12915511.

It is an arithmetic number, because the mean of its divisors is an integer number (12915511).

Almost surely, 2^25831021 is an apocalyptic number.

It is an amenable number.

25831021 is a deficient number, since it is larger than the sum of its proper divisors (1).

25831021 is an equidigital number, since it uses as much as digits as its factorization.

25831021 is an evil number, because the sum of its binary digits is even.

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

The square root of 25831021 is about 5082.4227490440. The cubic root of 25831021 is about 295.6064170283.

Adding to 25831021 its reverse (12013852), we get a palindrome (37844873).

The spelling of 25831021 in words is "twenty-five million, eight hundred thirty-one thousand, twenty-one".