401322781 has 4 divisors (see below), whose sum is σ = 401363100. Its totient is φ = 401282464.

The previous prime is 401322751. The next prime is 401322787. The reversal of 401322781 is 187223104.

401322781 = 14165² + 14166².

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 200647225 + 200675556 = 14165^2 + 14166^2 .

It is a cyclic number.

It is not a de Polignac number, because 401322781 - 2⁵ = 401322749 is a prime.

It is a super-2 number, since 2×401322781² = 322119949099147922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (401322787) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6705 + ... + 29113.

It is an arithmetic number, because the mean of its divisors is an integer number (100340775).

Almost surely, 2^401322781 is an apocalyptic number.

401322781 is the 14166-th centered square number.

It is an amenable number.

401322781 is a deficient number, since it is larger than the sum of its proper divisors (40319).

401322781 is a wasteful number, since it uses less digits than its factorization.

401322781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40318.

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 401322781 is about 20033.0422302755. The cubic root of 401322781 is about 737.6176005514.

Adding to 401322781 its reverse (187223104), we get a palindrome (588545885).

The spelling of 401322781 in words is "four hundred one million, three hundred twenty-two thousand, seven hundred eighty-one".