381554666 has 4 divisors (see below), whose sum is σ = 572332002. Its totient is φ = 190777332.

The previous prime is 381554633. The next prime is 381554687. The reversal of 381554666 is 666455183.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 666455183 = 401 ⋅1661983.

It can be written as a sum of positive squares in only one way, i.e., 284630641 + 96924025 = 16871^2 + 9845^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95388665 + ... + 95388668.

Almost surely, 2^381554666 is an apocalyptic number.

381554666 is a deficient number, since it is larger than the sum of its proper divisors (190777336).

381554666 is a wasteful number, since it uses less digits than its factorization.

381554666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 190777335.

The product of its digits is 518400, while the sum is 44.

The square root of 381554666 is about 19533.4243285708. The cubic root of 381554666 is about 725.3020800625.

The spelling of 381554666 in words is "three hundred eighty-one million, five hundred fifty-four thousand, six hundred sixty-six".