401320561 has 2 divisors, whose sum is σ = 401320562. Its totient is φ = 401320560.

The previous prime is 401320559. The next prime is 401320567. The reversal of 401320561 is 165023104.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 311734336 + 89586225 = 17656^2 + 9465^2 .

It is a cyclic number.

It is not a de Polignac number, because 401320561 - 2¹ = 401320559 is a prime.

It is a super-2 number, since 2×401320561² = 322116385362709442, which contains 22 as substring.

Together with 401320559, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (401320567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200660280 + 200660281.

It is an arithmetic number, because the mean of its divisors is an integer number (200660281).

Almost surely, 2^401320561 is an apocalyptic number.

It is an amenable number.

401320561 is a deficient number, since it is larger than the sum of its proper divisors (1).

401320561 is an equidigital number, since it uses as much as digits as its factorization.

401320561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 401320561 is about 20032.9868217398. The cubic root of 401320561 is about 737.6162404541.

Adding to 401320561 its reverse (165023104), we get a palindrome (566343665).

The spelling of 401320561 in words is "four hundred one million, three hundred twenty thousand, five hundred sixty-one".