43631381 has 2 divisors, whose sum is σ = 43631382. Its totient is φ = 43631380.

The previous prime is 43631377. The next prime is 43631459. The reversal of 43631381 is 18313634.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 41396356 + 2235025 = 6434^2 + 1495^2 .

It is a cyclic number.

It is not a de Polignac number, because 43631381 - 2² = 43631377 is a prime.

It is a super-2 number, since 2×43631381² = 3807394815934322, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43631321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21815690 + 21815691.

It is an arithmetic number, because the mean of its divisors is an integer number (21815691).

Almost surely, 2^43631381 is an apocalyptic number.

It is an amenable number.

43631381 is a deficient number, since it is larger than the sum of its proper divisors (1).

43631381 is an equidigital number, since it uses as much as digits as its factorization.

43631381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5184, while the sum is 29.

The square root of 43631381 is about 6605.4054379728. The cubic root of 43631381 is about 352.0461936837.

The spelling of 43631381 in words is "forty-three million, six hundred thirty-one thousand, three hundred eighty-one".