381312981 has 16 divisors (see below), whose sum is σ = 645609600. Its totient is φ = 217893024.

The previous prime is 381312977. The next prime is 381312983. The reversal of 381312981 is 189213183.

It is not a de Polignac number, because 381312981 - 2² = 381312977 is a prime.

It is a super-2 number, since 2×381312981² = 290799178958212722, which contains 22 as substring.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (381312983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1008576 + ... + 1008953.

It is an arithmetic number, because the mean of its divisors is an integer number (40350600).

Almost surely, 2^381312981 is an apocalyptic number.

It is an amenable number.

381312981 is a deficient number, since it is larger than the sum of its proper divisors (264296619).

381312981 is a wasteful number, since it uses less digits than its factorization.

381312981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2017545 (or 2017539 counting only the distinct ones).

The product of its digits is 10368, while the sum is 36.

The square root of 381312981 is about 19527.2369013130. The cubic root of 381312981 is about 725.1489070280.

The spelling of 381312981 in words is "three hundred eighty-one million, three hundred twelve thousand, nine hundred eighty-one".