1981185306 has 16 divisors (see below), whose sum is σ = 3963071424. Its totient is φ = 660278304.

The previous prime is 1981185299. The next prime is 1981185307. The reversal of 1981185306 is 6035811891.

It is not an unprimeable number, because it can be changed into a prime (1981185307) 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 7 ways as a sum of consecutive naturals, for example, 12030 + ... + 64086.

It is an arithmetic number, because the mean of its divisors is an integer number (247691964).

Almost surely, 2^1981185306 is an apocalyptic number.

1981185306 is an abundant number, since it is smaller than the sum of its proper divisors (1981886118).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1981185306 is a wasteful number, since it uses less digits than its factorization.

1981185306 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58405.

The product of its (nonzero) digits is 51840, while the sum is 42.

The square root of 1981185306 is about 44510.5078155709. The cubic root of 1981185306 is about 1255.9577575993.

The spelling of 1981185306 in words is "one billion, nine hundred eighty-one million, one hundred eighty-five thousand, three hundred six".