1981224681 has 8 divisors (see below), whose sum is σ = 2713028544. Its totient is φ = 1285118640.

The previous prime is 1981224667. The next prime is 1981224731. The reversal of 1981224681 is 1864221891.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1981224681 - 2⁵ = 1981224649 is a prime.

It is a super-3 number, since 3×1981224681³ (a number of 29 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not an unprimeable number, because it can be changed into a prime (1981224611) 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, 8924325 + ... + 8924546.

It is an arithmetic number, because the mean of its divisors is an integer number (339128568).

Almost surely, 2^1981224681 is an apocalyptic number.

It is an amenable number.

1981224681 is a deficient number, since it is larger than the sum of its proper divisors (731803863).

1981224681 is a wasteful number, since it uses less digits than its factorization.

1981224681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17848911.

The product of its digits is 55296, while the sum is 42.

The square root of 1981224681 is about 44510.9501246603. The cubic root of 1981224681 is about 1255.9660780407.

The spelling of 1981224681 in words is "one billion, nine hundred eighty-one million, two hundred twenty-four thousand, six hundred eighty-one".