401665441 has 2 divisors, whose sum is σ = 401665442. Its totient is φ = 401665440.

The previous prime is 401665427. The next prime is 401665447. The reversal of 401665441 is 144566104.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 376515216 + 25150225 = 19404^2 + 5015^2 .

It is a cyclic number.

It is not a de Polignac number, because 401665441 - 2⁹ = 401664929 is a prime.

It is a super-2 number, since 2×401665441² = 322670252987448962, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (401665447) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200832720 + 200832721.

It is an arithmetic number, because the mean of its divisors is an integer number (200832721).

Almost surely, 2^401665441 is an apocalyptic number.

It is an amenable number.

401665441 is a deficient number, since it is larger than the sum of its proper divisors (1).

401665441 is an equidigital number, since it uses as much as digits as its factorization.

401665441 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11520, while the sum is 31.

The square root of 401665441 is about 20041.5927760246. The cubic root of 401665441 is about 737.8274733002.

The spelling of 401665441 in words is "four hundred one million, six hundred sixty-five thousand, four hundred forty-one".