40608781 has 2 divisors, whose sum is σ = 40608782. Its totient is φ = 40608780.

The previous prime is 40608769. The next prime is 40608811. The reversal of 40608781 is 18780604.

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., 34703881 + 5904900 = 5891^2 + 2430^2 .

It is a cyclic number.

It is not a de Polignac number, because 40608781 - 2⁵ = 40608749 is a prime.

It is a super-2 number, since 2×40608781² = 3298146188611922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40608751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20304390 + 20304391.

It is an arithmetic number, because the mean of its divisors is an integer number (20304391).

Almost surely, 2^40608781 is an apocalyptic number.

It is an amenable number.

40608781 is a deficient number, since it is larger than the sum of its proper divisors (1).

40608781 is an equidigital number, since it uses as much as digits as its factorization.

40608781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10752, while the sum is 34.

The square root of 40608781 is about 6372.5019419377. The cubic root of 40608781 is about 343.7214624904.

The spelling of 40608781 in words is "forty million, six hundred eight thousand, seven hundred eighty-one".