1851811797 has 16 divisors (see below), whose sum is σ = 2750856192. Its totient is φ = 1098430320.

The previous prime is 1851811789. The next prime is 1851811823. The reversal of 1851811797 is 7971181581.

It is not a de Polignac number, because 1851811797 - 2³ = 1851811789 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1851811777) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 595423 + ... + 598524.

It is an arithmetic number, because the mean of its divisors is an integer number (171928512).

Almost surely, 2^1851811797 is an apocalyptic number.

It is an amenable number.

1851811797 is a deficient number, since it is larger than the sum of its proper divisors (899044395).

1851811797 is a wasteful number, since it uses less digits than its factorization.

1851811797 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1194008.

The product of its digits is 141120, while the sum is 48.

The square root of 1851811797 is about 43032.6828933544. The cubic root of 1851811797 is about 1228.0016456828.

It can be divided in two parts, 18 and 51811797, that added together give a palindrome (51811815).

The spelling of 1851811797 in words is "one billion, eight hundred fifty-one million, eight hundred eleven thousand, seven hundred ninety-seven".