381376721 has 16 divisors (see below), whose sum is σ = 441988800. Its totient is φ = 325425600.

The previous prime is 381376717. The next prime is 381376741. The reversal of 381376721 is 127673183.

It is a cyclic number.

It is not a de Polignac number, because 381376721 - 2² = 381376717 is a prime.

It is not an unprimeable number, because it can be changed into a prime (381376741) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14411 + ... + 31151.

It is an arithmetic number, because the mean of its divisors is an integer number (27624300).

Almost surely, 2^381376721 is an apocalyptic number.

It is an amenable number.

381376721 is a deficient number, since it is larger than the sum of its proper divisors (60612079).

381376721 is a wasteful number, since it uses less digits than its factorization.

381376721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16880.

The product of its digits is 42336, while the sum is 38.

The square root of 381376721 is about 19528.8689124588. The cubic root of 381376721 is about 725.1893098978.

The spelling of 381376721 in words is "three hundred eighty-one million, three hundred seventy-six thousand, seven hundred twenty-one".