251798081909 has 16 divisors (see below), whose sum is σ = 295187996736. Its totient is φ = 212226643200.

The previous prime is 251798081819. The next prime is 251798081911. The reversal of 251798081909 is 909180897152.

251798081909 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 251798081909 - 2¹² = 251798077813 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251798081999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10036082 + ... + 10061139.

It is an arithmetic number, because the mean of its divisors is an integer number (18449249796).

Almost surely, 2^251798081909 is an apocalyptic number.

It is an amenable number.

251798081909 is a deficient number, since it is larger than the sum of its proper divisors (43389914827).

251798081909 is a wasteful number, since it uses less digits than its factorization.

251798081909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20097316.

The product of its (nonzero) digits is 3265920, while the sum is 59.

The spelling of 251798081909 in words is "two hundred fifty-one billion, seven hundred ninety-eight million, eighty-one thousand, nine hundred nine".