381390687 has 24 divisors (see below), whose sum is σ = 591012240. Its totient is φ = 245488320.

The previous prime is 381390683. The next prime is 381390697. The reversal of 381390687 is 786093183.

It is a happy number.

It is not a de Polignac number, because 381390687 - 2² = 381390683 is a prime.

It is a super-2 number, since 2×381390687² = 290917712260663938, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (381390683) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 20014 + ... + 34107.

It is an arithmetic number, because the mean of its divisors is an integer number (24625510).

Almost surely, 2^381390687 is an apocalyptic number.

381390687 is a deficient number, since it is larger than the sum of its proper divisors (209621553).

381390687 is an equidigital number, since it uses as much as digits as its factorization.

381390687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54165 (or 54153 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The square root of 381390687 is about 19529.2264823776. The cubic root of 381390687 is about 725.1981619241.

The spelling of 381390687 in words is "three hundred eighty-one million, three hundred ninety thousand, six hundred eighty-seven".