1893993981 has 16 divisors (see below), whose sum is σ = 2773396800. Its totient is φ = 1140168320.

The previous prime is 1893993923. The next prime is 1893994001.

1893993981 is nontrivially palindromic in base 10.

It is a cyclic number.

It is not a de Polignac number, because 1893993981 - 2¹³ = 1893985789 is a prime.

It is a super-2 number, since 2×1893993981² = 7174426400128456722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1893993911) 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 15 ways as a sum of consecutive naturals, for example, 187680 + ... + 197513.

It is an arithmetic number, because the mean of its divisors is an integer number (173337300).

Almost surely, 2^1893993981 is an apocalyptic number.

1893993981 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1893993981 is a deficient number, since it is larger than the sum of its proper divisors (879402819).

1893993981 is a wasteful number, since it uses less digits than its factorization.

1893993981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 385356.

The product of its digits is 3779136, while the sum is 60.

The square root of 1893993981 is about 43520.0411419842. The cubic root of 1893993981 is about 1237.2558943881.

The spelling of 1893993981 in words is "one billion, eight hundred ninety-three million, nine hundred ninety-three thousand, nine hundred eighty-one".