400312421 has 2 divisors, whose sum is σ = 400312422. Its totient is φ = 400312420.

The previous prime is 400312313. The next prime is 400312427. The reversal of 400312421 is 124213004.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 334524100 + 65788321 = 18290^2 + 8111^2 .

It is a cyclic number.

It is not a de Polignac number, because 400312421 - 2¹⁴ = 400296037 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 400312421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (400312427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200156210 + 200156211.

It is an arithmetic number, because the mean of its divisors is an integer number (200156211).

Almost surely, 2^400312421 is an apocalyptic number.

It is an amenable number.

400312421 is a deficient number, since it is larger than the sum of its proper divisors (1).

400312421 is an equidigital number, since it uses as much as digits as its factorization.

400312421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 400312421 is about 20007.8090004878. The cubic root of 400312421 is about 736.9980779413.

Adding to 400312421 its reverse (124213004), we get a palindrome (524525425).

The spelling of 400312421 in words is "four hundred million, three hundred twelve thousand, four hundred twenty-one".