18845220257 has 8 divisors (see below), whose sum is σ = 19264886760. Its totient is φ = 18429125760.

The previous prime is 18845220221. The next prime is 18845220263. The reversal of 18845220257 is 75202254881.

It can be written as a sum of positive squares in 4 ways, for example, as 164891281 + 18680328976 = 12841^2 + 136676^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18845220257 - 2¹⁸ = 18844958113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18845220217) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 882332 + ... + 903437.

It is an arithmetic number, because the mean of its divisors is an integer number (2408110845).

Almost surely, 2^18845220257 is an apocalyptic number.

It is an amenable number.

18845220257 is a deficient number, since it is larger than the sum of its proper divisors (419666503).

18845220257 is a wasteful number, since it uses less digits than its factorization.

18845220257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1786003.

The product of its (nonzero) digits is 358400, while the sum is 44.

The spelling of 18845220257 in words is "eighteen billion, eight hundred forty-five million, two hundred twenty thousand, two hundred fifty-seven".