1981331367 has 4 divisors (see below), whose sum is σ = 2641775160. Its totient is φ = 1320887576.

The previous prime is 1981331357. The next prime is 1981331369. The reversal of 1981331367 is 7631331891.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1981331367 - 2¹⁹ = 1980807079 is a prime.

It is a super-3 number, since 3×1981331367³ (a number of 29 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981331369) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 330221892 + ... + 330221897.

It is an arithmetic number, because the mean of its divisors is an integer number (660443790).

Almost surely, 2^1981331367 is an apocalyptic number.

1981331367 is a deficient number, since it is larger than the sum of its proper divisors (660443793).

1981331367 is an equidigital number, since it uses as much as digits as its factorization.

1981331367 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 660443792.

The product of its digits is 81648, while the sum is 42.

The square root of 1981331367 is about 44512.1485327321. The cubic root of 1981331367 is about 1255.9886216040.

The spelling of 1981331367 in words is "one billion, nine hundred eighty-one million, three hundred thirty-one thousand, three hundred sixty-seven".