40656191 has 2 divisors, whose sum is σ = 40656192. Its totient is φ = 40656190.

The previous prime is 40656169. The next prime is 40656193. The reversal of 40656191 is 19165604.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-40656191 is a prime.

Together with 40656193, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40656193) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20328095 + 20328096.

It is an arithmetic number, because the mean of its divisors is an integer number (20328096).

Almost surely, 2^40656191 is an apocalyptic number.

40656191 is a deficient number, since it is larger than the sum of its proper divisors (1).

40656191 is an equidigital number, since it uses as much as digits as its factorization.

40656191 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6480, while the sum is 32.

The square root of 40656191 is about 6376.2207458651. The cubic root of 40656191 is about 343.8551732836.

The spelling of 40656191 in words is "forty million, six hundred fifty-six thousand, one hundred ninety-one".