25801520161993 has 2 divisors, whose sum is σ = 25801520161994. Its totient is φ = 25801520161992.

The previous prime is 25801520161961. The next prime is 25801520162027. The reversal of 25801520161993 is 39916102510852.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 24900818565184 + 900701596809 = 4990072^2 + 949053^2 .

It is a cyclic number.

It is not a de Polignac number, because 25801520161993 - 2⁵ = 25801520161961 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 25801520161993.

It is not a weakly prime, because it can be changed into another prime (25801520161933) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12900760080996 + 12900760080997.

It is an arithmetic number, because the mean of its divisors is an integer number (12900760080997).

Almost surely, 2^{25801520161993} is an apocalyptic number.

It is an amenable number.

25801520161993 is a deficient number, since it is larger than the sum of its proper divisors (1).

25801520161993 is an equidigital number, since it uses as much as digits as its factorization.

25801520161993 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1166400, while the sum is 52.

The spelling of 25801520161993 in words is "twenty-five trillion, eight hundred one billion, five hundred twenty million, one hundred sixty-one thousand, nine hundred ninety-three".