401800121 has 2 divisors, whose sum is σ = 401800122. Its totient is φ = 401800120.

The previous prime is 401800111. The next prime is 401800129. The reversal of 401800121 is 121008104.

Added to its reverse (121008104) it gives a square (522808225 = 22865²).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 223951225 + 177848896 = 14965^2 + 13336^2 .

It is a cyclic number.

It is not a de Polignac number, because 401800121 - 2¹⁴ = 401783737 is a prime.

It is a super-2 number, since 2×401800121² = 322886674471229282, which contains 22 as substring.

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 401800121.

It is not a weakly prime, because it can be changed into another prime (401800129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200900060 + 200900061.

It is an arithmetic number, because the mean of its divisors is an integer number (200900061).

Almost surely, 2^401800121 is an apocalyptic number.

It is an amenable number.

401800121 is a deficient number, since it is larger than the sum of its proper divisors (1).

401800121 is an equidigital number, since it uses as much as digits as its factorization.

401800121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64, while the sum is 17.

The square root of 401800121 is about 20044.9525068033. The cubic root of 401800121 is about 737.9099295682.

Adding to 401800121 its reverse (121008104), we get a palindrome (522808225).

The spelling of 401800121 in words is "four hundred one million, eight hundred thousand, one hundred twenty-one".