381187731 has 16 divisors (see below), whose sum is σ = 517835520. Its totient is φ = 249348960.

The previous prime is 381187693. The next prime is 381187739. The reversal of 381187731 is 137781183.

It is not a de Polignac number, because 381187731 - 2⁷ = 381187603 is a prime.

It is a super-2 number, since 2×381187731² = 290608172529856722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 381187731.

It is not an unprimeable number, because it can be changed into a prime (381187739) 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, 109981 + ... + 113393.

It is an arithmetic number, because the mean of its divisors is an integer number (32364720).

Almost surely, 2^381187731 is an apocalyptic number.

381187731 is a deficient number, since it is larger than the sum of its proper divisors (136647789).

381187731 is a wasteful number, since it uses less digits than its factorization.

381187731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4106.

The product of its digits is 28224, while the sum is 39.

The square root of 381187731 is about 19524.0295789573. The cubic root of 381187731 is about 725.0695017001.

The spelling of 381187731 in words is "three hundred eighty-one million, one hundred eighty-seven thousand, seven hundred thirty-one".