3855385861 has 2 divisors, whose sum is σ = 3855385862. Its totient is φ = 3855385860.

The previous prime is 3855385843. The next prime is 3855385913. The reversal of 3855385861 is 1685835583.

3855385861 = 43905² + 43906².

It is an a-pointer prime, because the next prime (3855385913) can be obtained adding 3855385861 to its sum of digits (52).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1927736836 + 1927649025 = 43906^2 + 43905^2 .

It is a cyclic number.

It is not a de Polignac number, because 3855385861 - 2⁷ = 3855385733 is a prime.

It is a super-2 number, since 2×3855385861² = 29728000274397422642, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 3855385799 and 3855385808.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3855385561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1927692930 + 1927692931.

It is an arithmetic number, because the mean of its divisors is an integer number (1927692931).

Almost surely, 2^3855385861 is an apocalyptic number.

3855385861 is the 43906-th centered square number.

It is an amenable number.

3855385861 is a deficient number, since it is larger than the sum of its proper divisors (1).

3855385861 is an equidigital number, since it uses as much as digits as its factorization.

3855385861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3456000, while the sum is 52.

The square root of 3855385861 is about 62091.7535667982. The cubic root of 3855385861 is about 1568.0357141501.

The spelling of 3855385861 in words is "three billion, eight hundred fifty-five million, three hundred eighty-five thousand, eight hundred sixty-one".