6381951381 has 96 divisors (see below), whose sum is σ = 10925591040. Its totient is φ = 3556320768.

The previous prime is 6381951349. The next prime is 6381951397. The reversal of 6381951381 is 1831591836.

It is a happy number.

6381951381 is a `hidden beast` number, since 638 + 1 + 9 + 5 + 1 + 3 + 8 + 1 = 666.

6381951381 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 6381951381 - 2⁵ = 6381951349 is a prime.

It is a super-2 number, since 2×6381951381² = 81458606858895614322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6381951311) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 4135296 + ... + 4136838.

It is an arithmetic number, because the mean of its divisors is an integer number (113808240).

Almost surely, 2^6381951381 is an apocalyptic number.

It is an amenable number.

6381951381 is a deficient number, since it is larger than the sum of its proper divisors (4543639659).

6381951381 is a wasteful number, since it uses less digits than its factorization.

6381951381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1667 (or 1664 counting only the distinct ones).

The product of its digits is 155520, while the sum is 45.

The square root of 6381951381 is about 79887.1164894565. The cubic root of 6381951381 is about 1854.8885929756. Note that the first 3 decimals are identical.

The spelling of 6381951381 in words is "six billion, three hundred eighty-one million, nine hundred fifty-one thousand, three hundred eighty-one".