406696991 has 2 divisors, whose sum is σ = 406696992. Its totient is φ = 406696990.

The previous prime is 406696949. The next prime is 406697009. The reversal of 406696991 is 199696604.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-406696991 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (406696391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 203348495 + 203348496.

It is an arithmetic number, because the mean of its divisors is an integer number (203348496).

Almost surely, 2^406696991 is an apocalyptic number.

406696991 is a deficient number, since it is larger than the sum of its proper divisors (1).

406696991 is an equidigital number, since it uses as much as digits as its factorization.

406696991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 629856, while the sum is 50.

The square root of 406696991 is about 20166.7298043089. The cubic root of 406696991 is about 740.8955501700.

The spelling of 406696991 in words is "four hundred six million, six hundred ninety-six thousand, nine hundred ninety-one".