1855216705 has 4 divisors (see below), whose sum is σ = 2226260052. Its totient is φ = 1484173360.

The previous prime is 1855216691. The next prime is 1855216763. The reversal of 1855216705 is 5076125581.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5076125581 = 41 ⋅123807941.

It can be written as a sum of positive squares in 2 ways, for example, as 1368926001 + 486290704 = 36999^2 + 22052^2 .

It is not a de Polignac number, because 1855216705 - 2⁵ = 1855216673 is a prime.

It is a super-2 number, since 2×1855216705² = 6883658045022114050, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 185521666 + ... + 185521675.

It is an arithmetic number, because the mean of its divisors is an integer number (556565013).

Almost surely, 2^1855216705 is an apocalyptic number.

It is an amenable number.

1855216705 is a deficient number, since it is larger than the sum of its proper divisors (371043347).

1855216705 is an equidigital number, since it uses as much as digits as its factorization.

1855216705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 371043346.

The product of its (nonzero) digits is 84000, while the sum is 40.

The square root of 1855216705 is about 43072.2266083378. The cubic root of 1855216705 is about 1228.7538230162.

The spelling of 1855216705 in words is "one billion, eight hundred fifty-five million, two hundred sixteen thousand, seven hundred five".