40556381 has 2 divisors, whose sum is σ = 40556382. Its totient is φ = 40556380.

The previous prime is 40556377. The next prime is 40556419. The reversal of 40556381 is 18365504.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 40208281 + 348100 = 6341^2 + 590^2 .

It is a cyclic number.

It is not a de Polignac number, because 40556381 - 2² = 40556377 is a prime.

It is a super-2 number, since 2×40556381² = 3289640079634322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40556311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20278190 + 20278191.

It is an arithmetic number, because the mean of its divisors is an integer number (20278191).

Almost surely, 2^40556381 is an apocalyptic number.

It is an amenable number.

40556381 is a deficient number, since it is larger than the sum of its proper divisors (1).

40556381 is an equidigital number, since it uses as much as digits as its factorization.

40556381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14400, while the sum is 32.

The square root of 40556381 is about 6368.3891997898. The cubic root of 40556381 is about 343.5735572291.

The spelling of 40556381 in words is "forty million, five hundred fifty-six thousand, three hundred eighty-one".