25998781 has 2 divisors, whose sum is σ = 25998782. Its totient is φ = 25998780.

The previous prime is 25998767. The next prime is 25998799. The reversal of 25998781 is 18789952.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22992025 + 3006756 = 4795^2 + 1734^2 .

It is a cyclic number.

It is not a de Polignac number, because 25998781 - 2¹³ = 25990589 is a prime.

It is a super-2 number, since 2×25998781² = 1351873226971922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25998481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12999390 + 12999391.

It is an arithmetic number, because the mean of its divisors is an integer number (12999391).

Almost surely, 2^25998781 is an apocalyptic number.

It is an amenable number.

25998781 is a deficient number, since it is larger than the sum of its proper divisors (1).

25998781 is an equidigital number, since it uses as much as digits as its factorization.

25998781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 362880, while the sum is 49.

The square root of 25998781 is about 5098.8999794073. The cubic root of 25998781 is about 296.2449769188.

The spelling of 25998781 in words is "twenty-five million, nine hundred ninety-eight thousand, seven hundred eighty-one".