1850518381 has 4 divisors (see below), whose sum is σ = 1851508252. Its totient is φ = 1849528512.

The previous prime is 1850518379. The next prime is 1850518403. The reversal of 1850518381 is 1838150581.

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 477815881 + 1372702500 = 21859^2 + 37050^2 .

It is a cyclic number.

It is not a de Polignac number, because 1850518381 - 2¹ = 1850518379 is a prime.

It is a super-2 number, since 2×1850518381² = 6848836556837722322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1850518081) 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, 492126 + ... + 495871.

It is an arithmetic number, because the mean of its divisors is an integer number (462877063).

Almost surely, 2^1850518381 is an apocalyptic number.

It is an amenable number.

1850518381 is a deficient number, since it is larger than the sum of its proper divisors (989871).

1850518381 is an equidigital number, since it uses as much as digits as its factorization.

1850518381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 989870.

The product of its (nonzero) digits is 38400, while the sum is 40.

The square root of 1850518381 is about 43017.6519698600. The cubic root of 1850518381 is about 1227.7156758532.

The spelling of 1850518381 in words is "one billion, eight hundred fifty million, five hundred eighteen thousand, three hundred eighty-one".