401375581 has 2 divisors, whose sum is σ = 401375582. Its totient is φ = 401375580.

The previous prime is 401375563. The next prime is 401375641. The reversal of 401375581 is 185573104.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 390260025 + 11115556 = 19755^2 + 3334^2 .

It is a cyclic number.

It is not a de Polignac number, because 401375581 - 2⁵ = 401375549 is a prime.

It is a super-2 number, since 2×401375581² = 322204714046175122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (401375521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200687790 + 200687791.

It is an arithmetic number, because the mean of its divisors is an integer number (200687791).

Almost surely, 2^401375581 is an apocalyptic number.

It is an amenable number.

401375581 is a deficient number, since it is larger than the sum of its proper divisors (1).

401375581 is an equidigital number, since it uses as much as digits as its factorization.

401375581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16800, while the sum is 34.

The square root of 401375581 is about 20034.3600097433. The cubic root of 401375581 is about 737.6499473333.

It can be divided in two parts, 401375 and 581, that added together give a square (401956 = 634²).

The spelling of 401375581 in words is "four hundred one million, three hundred seventy-five thousand, five hundred eighty-one".