40556591 has 2 divisors, whose sum is σ = 40556592. Its totient is φ = 40556590.

The previous prime is 40556557. The next prime is 40556599. The reversal of 40556591 is 19565504.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 40556591 - 2¹⁸ = 40294447 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40556599) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20278295 + 20278296.

It is an arithmetic number, because the mean of its divisors is an integer number (20278296).

Almost surely, 2^40556591 is an apocalyptic number.

40556591 is a deficient number, since it is larger than the sum of its proper divisors (1).

40556591 is an equidigital number, since it uses as much as digits as its factorization.

40556591 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 27000, while the sum is 35.

The square root of 40556591 is about 6368.4056874543. The cubic root of 40556591 is about 343.5741502334.

The spelling of 40556591 in words is "forty million, five hundred fifty-six thousand, five hundred ninety-one".