40278181 has 2 divisors, whose sum is σ = 40278182. Its totient is φ = 40278180.

The previous prime is 40278167. The next prime is 40278209. The reversal of 40278181 is 18187204.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22562500 + 17715681 = 4750^2 + 4209^2 .

It is a cyclic number.

It is not a de Polignac number, because 40278181 - 2⁵ = 40278149 is a prime.

It is a super-2 number, since 2×40278181² = 3244663729337522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40278101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20139090 + 20139091.

It is an arithmetic number, because the mean of its divisors is an integer number (20139091).

Almost surely, 2^40278181 is an apocalyptic number.

It is an amenable number.

40278181 is a deficient number, since it is larger than the sum of its proper divisors (1).

40278181 is an equidigital number, since it uses as much as digits as its factorization.

40278181 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3584, while the sum is 31.

The square root of 40278181 is about 6346.5093555434. The cubic root of 40278181 is about 342.7861632414.

The spelling of 40278181 in words is "forty million, two hundred seventy-eight thousand, one hundred eighty-one".