31000381 has 8 divisors (see below), whose sum is σ = 32741280. Its totient is φ = 29270448.

The previous prime is 31000351. The next prime is 31000397. The reversal of 31000381 is 18300013.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 31000381 - 2⁵ = 31000349 is a prime.

It is a super-2 number, since 2×31000381² = 1922047244290322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31000301) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3450 + ... + 8596.

It is an arithmetic number, because the mean of its divisors is an integer number (4092660).

Almost surely, 2^31000381 is an apocalyptic number.

It is an amenable number.

31000381 is a deficient number, since it is larger than the sum of its proper divisors (1740899).

31000381 is a wasteful number, since it uses less digits than its factorization.

31000381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5483.

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 31000381 is about 5567.7985775349. The cubic root of 31000381 is about 314.1393521866.

Adding to 31000381 its reverse (18300013), we get a palindrome (49300394).

The spelling of 31000381 in words is "thirty-one million, three hundred eighty-one", and thus it is an aban number.