400420591 has 2 divisors, whose sum is σ = 400420592. Its totient is φ = 400420590.

The previous prime is 400420571. The next prime is 400420597. The reversal of 400420591 is 195024004.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-400420591 is a prime.

It is a plaindrome in base 16.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (400420597) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200210295 + 200210296.

It is an arithmetic number, because the mean of its divisors is an integer number (200210296).

Almost surely, 2^400420591 is an apocalyptic number.

400420591 is a deficient number, since it is larger than the sum of its proper divisors (1).

400420591 is an equidigital number, since it uses as much as digits as its factorization.

400420591 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 400420591 is about 20010.5120124399. The cubic root of 400420591 is about 737.0644543500.

Adding to 400420591 its reverse (195024004), we get a palindrome (595444595).

The spelling of 400420591 in words is "four hundred million, four hundred twenty thousand, five hundred ninety-one".