1025681639 has 2 divisors, whose sum is σ = 1025681640. Its totient is φ = 1025681638.

The previous prime is 1025681561. The next prime is 1025681641. The reversal of 1025681639 is 9361865201.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1025681639 - 2²⁸ = 757246183 is a prime.

Together with 1025681641, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 1025681596 and 1025681605.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1025681659) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 512840819 + 512840820.

It is an arithmetic number, because the mean of its divisors is an integer number (512840820).

Almost surely, 2^1025681639 is an apocalyptic number.

1025681639 is a deficient number, since it is larger than the sum of its proper divisors (1).

1025681639 is an equidigital number, since it uses as much as digits as its factorization.

1025681639 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 77760, while the sum is 41.

The square root of 1025681639 is about 32026.2648306043. The cubic root of 1025681639 is about 1008.4882913792.

The spelling of 1025681639 in words is "one billion, twenty-five million, six hundred eighty-one thousand, six hundred thirty-nine".