1855623109 has 2 divisors, whose sum is σ = 1855623110. Its totient is φ = 1855623108.

The previous prime is 1855623103. The next prime is 1855623113. The reversal of 1855623109 is 9013265581.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1850892484 + 4730625 = 43022^2 + 2175^2 .

It is a cyclic number.

It is not a de Polignac number, because 1855623109 - 2²⁷ = 1721405381 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1855623103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 927811554 + 927811555.

It is an arithmetic number, because the mean of its divisors is an integer number (927811555).

Almost surely, 2^1855623109 is an apocalyptic number.

It is an amenable number.

1855623109 is a deficient number, since it is larger than the sum of its proper divisors (1).

1855623109 is an equidigital number, since it uses as much as digits as its factorization.

1855623109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64800, while the sum is 40.

The square root of 1855623109 is about 43076.9440536350. The cubic root of 1855623109 is about 1228.8435401200.

The spelling of 1855623109 in words is "one billion, eight hundred fifty-five million, six hundred twenty-three thousand, one hundred nine".