400846991 has 2 divisors, whose sum is σ = 400846992. Its totient is φ = 400846990.

The previous prime is 400846987. The next prime is 400846993. The reversal of 400846991 is 199648004.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 400846991 - 2² = 400846987 is a prime.

It is a Sophie Germain prime.

Together with 400846993, 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 (400846993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200423495 + 200423496.

It is an arithmetic number, because the mean of its divisors is an integer number (200423496).

Almost surely, 2^400846991 is an apocalyptic number.

400846991 is a deficient number, since it is larger than the sum of its proper divisors (1).

400846991 is an equidigital number, since it uses as much as digits as its factorization.

400846991 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 400846991 is about 20021.1635775746. The cubic root of 400846991 is about 737.3259900102.

The spelling of 400846991 in words is "four hundred million, eight hundred forty-six thousand, nine hundred ninety-one".