400220129 has 2 divisors, whose sum is σ = 400220130. Its totient is φ = 400220128.

The previous prime is 400220111. The next prime is 400220131. The reversal of 400220129 is 921022004.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 231739729 + 168480400 = 15223^2 + 12980^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-400220129 is a prime.

Together with 400220131, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 400220129.

It is not a weakly prime, because it can be changed into another prime (400220179) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200110064 + 200110065.

It is an arithmetic number, because the mean of its divisors is an integer number (200110065).

Almost surely, 2^400220129 is an apocalyptic number.

It is an amenable number.

400220129 is a deficient number, since it is larger than the sum of its proper divisors (1).

400220129 is an equidigital number, since it uses as much as digits as its factorization.

400220129 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 400220129 is about 20005.5024680711. The cubic root of 400220129 is about 736.9414353034.

The spelling of 400220129 in words is "four hundred million, two hundred twenty thousand, one hundred twenty-nine".