401641681 has 15 divisors (see below), whose sum is σ = 469702491. Its totient is φ = 343422576.

The previous prime is 401641631. The next prime is 401641687. The reversal of 401641681 is 186146104.

The square root of 401641681 is 20041.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 367067281 + 34574400 = 19159^2 + 5880^2 .

It is not a de Polignac number, because 401641681 - 2⁷ = 401641553 is a prime.

It is a super-2 number, since 2×401641681² = 322632079833011522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (401641687) by changing a digit.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 981805 + ... + 982213.

Almost surely, 2^401641681 is an apocalyptic number.

401641681 is the 20041-st square number.

401641681 is the 10021-st centered octagonal number.

It is an amenable number.

401641681 is a deficient number, since it is larger than the sum of its proper divisors (68060810).

401641681 is an frugal number, since it uses more digits than its factorization.

401641681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 846 (or 416 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 31.

The cubic root of 401641681 is about 737.8129246032.

Adding to 401641681 its reverse (186146104), we get a palindrome (587787785).

The spelling of 401641681 in words is "four hundred one million, six hundred forty-one thousand, six hundred eighty-one".