380405781 has 32 divisors (see below), whose sum is σ = 647193600. Its totient is φ = 216321840.

The previous prime is 380405759. The next prime is 380405807. The reversal of 380405781 is 187504083.

380405781 is a `hidden beast` number, since 3 + 80 + 4 + 0 + 578 + 1 = 666.

It is not a de Polignac number, because 380405781 - 2⁷ = 380405653 is a prime.

It is a super-2 number, since 2×380405781² = 289417116436439922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (380405741) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 35110 + ... + 44648.

It is an arithmetic number, because the mean of its divisors is an integer number (20224800).

Almost surely, 2^380405781 is an apocalyptic number.

It is an amenable number.

380405781 is a deficient number, since it is larger than the sum of its proper divisors (266787819).

380405781 is a wasteful number, since it uses less digits than its factorization.

380405781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9766 (or 9760 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 36.

The square root of 380405781 is about 19503.9939755938. The cubic root of 380405781 is about 724.5733715113.

The spelling of 380405781 in words is "three hundred eighty million, four hundred five thousand, seven hundred eighty-one".