381231780561 has 12 divisors (see below), whose sum is σ = 574610220288. Its totient is φ = 243104323704.

The previous prime is 381231780557. The next prime is 381231780623. The reversal of 381231780561 is 165087132183.

It is a happy number.

381231780561 is a `hidden beast` number, since 3 + 8 + 1 + 2 + 3 + 1 + 7 + 80 + 561 = 666.

It is not a de Polignac number, because 381231780561 - 2² = 381231780557 is a prime.

It is not an unprimeable number, because it can be changed into a prime (381231780541) 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 11 ways as a sum of consecutive naturals, for example, 920849505 + ... + 920849918.

It is an arithmetic number, because the mean of its divisors is an integer number (47884185024).

Almost surely, 2^381231780561 is an apocalyptic number.

It is an amenable number.

381231780561 is a deficient number, since it is larger than the sum of its proper divisors (193378439727).

381231780561 is a wasteful number, since it uses less digits than its factorization.

381231780561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1841699452 (or 1841699449 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 45.

The spelling of 381231780561 in words is "three hundred eighty-one billion, two hundred thirty-one million, seven hundred eighty thousand, five hundred sixty-one".