400002231991 has 2 divisors, whose sum is σ = 400002231992. Its totient is φ = 400002231990.

The previous prime is 400002231971. The next prime is 400002232057. The reversal of 400002231991 is 199132200004.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 400002231991 - 2²⁹ = 399465361079 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (400002231971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200001115995 + 200001115996.

It is an arithmetic number, because the mean of its divisors is an integer number (200001115996).

Almost surely, 2^400002231991 is an apocalyptic number.

400002231991 is a deficient number, since it is larger than the sum of its proper divisors (1).

400002231991 is an equidigital number, since it uses as much as digits as its factorization.

400002231991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3888, while the sum is 31.

Adding to 400002231991 its reverse (199132200004), we get a palindrome (599134431995).

The spelling of 400002231991 in words is "four hundred billion, two million, two hundred thirty-one thousand, nine hundred ninety-one".