25556670709 has 2 divisors, whose sum is σ = 25556670710. Its totient is φ = 25556670708.

The previous prime is 25556670691. The next prime is 25556670743. The reversal of 25556670709 is 90707665552.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20659750225 + 4896920484 = 143735^2 + 69978^2 .

It is a cyclic number.

It is not a de Polignac number, because 25556670709 - 2⁵ = 25556670677 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25556674709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12778335354 + 12778335355.

It is an arithmetic number, because the mean of its divisors is an integer number (12778335355).

Almost surely, 2^25556670709 is an apocalyptic number.

It is an amenable number.

25556670709 is a deficient number, since it is larger than the sum of its proper divisors (1).

25556670709 is an equidigital number, since it uses as much as digits as its factorization.

25556670709 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3969000, while the sum is 52.

The spelling of 25556670709 in words is "twenty-five billion, five hundred fifty-six million, six hundred seventy thousand, seven hundred nine".