1981860245 has 8 divisors (see below), whose sum is σ = 2379180600. Its totient is φ = 1584856000.

The previous prime is 1981860241. The next prime is 1981860259. The reversal of 1981860245 is 5420681891.

It can be written as a sum of positive squares in 4 ways, for example, as 717275524 + 1264584721 = 26782^2 + 35561^2 .

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

It is not a de Polignac number, because 1981860245 - 2² = 1981860241 is a prime.

It is a super-2 number, since 2×1981860245² = 7855540061422920050, which contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1981860196 and 1981860205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981860241) 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, 65006 + ... + 90495.

It is an arithmetic number, because the mean of its divisors is an integer number (297397575).

Almost surely, 2^1981860245 is an apocalyptic number.

It is an amenable number.

1981860245 is a deficient number, since it is larger than the sum of its proper divisors (397320355).

1981860245 is a wasteful number, since it uses less digits than its factorization.

1981860245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 158055.

The product of its (nonzero) digits is 138240, while the sum is 44.

The square root of 1981860245 is about 44518.0889639257. The cubic root of 1981860245 is about 1256.1003656003.

The spelling of 1981860245 in words is "one billion, nine hundred eighty-one million, eight hundred sixty thousand, two hundred forty-five".