400420291 has 2 divisors, whose sum is σ = 400420292. Its totient is φ = 400420290.

The previous prime is 400420259. The next prime is 400420331. The reversal of 400420291 is 192024004.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 400420291 - 2⁵ = 400420259 is a prime.

It is not a weakly prime, because it can be changed into another prime (400420591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200210145 + 200210146.

It is an arithmetic number, because the mean of its divisors is an integer number (200210146).

Almost surely, 2^400420291 is an apocalyptic number.

400420291 is a deficient number, since it is larger than the sum of its proper divisors (1).

400420291 is an equidigital number, since it uses as much as digits as its factorization.

400420291 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 400420291 is about 20010.5045163784. The cubic root of 400420291 is about 737.0642702773.

Adding to 400420291 its reverse (192024004), we get a palindrome (592444295).

The spelling of 400420291 in words is "four hundred million, four hundred twenty thousand, two hundred ninety-one".