400220591 has 2 divisors, whose sum is σ = 400220592. Its totient is φ = 400220590.

The previous prime is 400220549. The next prime is 400220593. The reversal of 400220591 is 195022004.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-400220591 is a prime.

Together with 400220593, 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 (400220593) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200110295 + 200110296.

It is an arithmetic number, because the mean of its divisors is an integer number (200110296).

Almost surely, 2^400220591 is an apocalyptic number.

400220591 is a deficient number, since it is larger than the sum of its proper divisors (1).

400220591 is an equidigital number, since it uses as much as digits as its factorization.

400220591 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 400220591 is about 20005.5140148910. The cubic root of 400220591 is about 736.9417188696.

Adding to 400220591 its reverse (195022004), we get a palindrome (595242595).

The spelling of 400220591 in words is "four hundred million, two hundred twenty thousand, five hundred ninety-one".