40689491 has 2 divisors, whose sum is σ = 40689492. Its totient is φ = 40689490.

The previous prime is 40689487. The next prime is 40689497. The reversal of 40689491 is 19498604.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 40689491 - 2² = 40689487 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (40689497) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20344745 + 20344746.

It is an arithmetic number, because the mean of its divisors is an integer number (20344746).

Almost surely, 2^40689491 is an apocalyptic number.

40689491 is a deficient number, since it is larger than the sum of its proper divisors (1).

40689491 is an equidigital number, since it uses as much as digits as its factorization.

40689491 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 62208, while the sum is 41.

The square root of 40689491 is about 6378.8314760621. The cubic root of 40689491 is about 343.9490273988.

The spelling of 40689491 in words is "forty million, six hundred eighty-nine thousand, four hundred ninety-one".