259681993 has 4 divisors (see below), whose sum is σ = 261577620. Its totient is φ = 257786368.

The previous prime is 259681991. The next prime is 259681997. The reversal of 259681993 is 399186952.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 47775744 + 211906249 = 6912^2 + 14557^2 .

It is a cyclic number.

It is not a de Polignac number, because 259681993 - 2¹ = 259681991 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 259681993.

It is not an unprimeable number, because it can be changed into a prime (259681991) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 947608 + ... + 947881.

It is an arithmetic number, because the mean of its divisors is an integer number (65394405).

Almost surely, 2^259681993 is an apocalyptic number.

It is an amenable number.

259681993 is a deficient number, since it is larger than the sum of its proper divisors (1895627).

259681993 is a wasteful number, since it uses less digits than its factorization.

259681993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1895626.

The product of its digits is 1049760, while the sum is 52.

The square root of 259681993 is about 16114.6515010409. The cubic root of 259681993 is about 637.9901082051.

The spelling of 259681993 in words is "two hundred fifty-nine million, six hundred eighty-one thousand, nine hundred ninety-three".