1851861769 has 2 divisors, whose sum is σ = 1851861770. Its totient is φ = 1851861768.

The previous prime is 1851861763. The next prime is 1851861773. The reversal of 1851861769 is 9671681581.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1783964169 + 67897600 = 42237^2 + 8240^2 .

It is a cyclic number.

It is not a de Polignac number, because 1851861769 - 2¹¹ = 1851859721 is a prime.

It is a super-2 number, since 2×1851861769² = 6858784022967618722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1851861763) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 925930884 + 925930885.

It is an arithmetic number, because the mean of its divisors is an integer number (925930885).

Almost surely, 2^1851861769 is an apocalyptic number.

It is an amenable number.

1851861769 is a deficient number, since it is larger than the sum of its proper divisors (1).

1851861769 is an equidigital number, since it uses as much as digits as its factorization.

1851861769 is an evil number, because the sum of its binary digits is even.

The product of its digits is 725760, while the sum is 52.

The square root of 1851861769 is about 43033.2635178881. The cubic root of 1851861769 is about 1228.0126916481.

The spelling of 1851861769 in words is "one billion, eight hundred fifty-one million, eight hundred sixty-one thousand, seven hundred sixty-nine".