401427781 has 2 divisors, whose sum is σ = 401427782. Its totient is φ = 401427780.

The previous prime is 401427751. The next prime is 401427791. The reversal of 401427781 is 187724104.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 298080225 + 103347556 = 17265^2 + 10166^2 .

It is a cyclic number.

It is not a de Polignac number, because 401427781 - 2¹⁹ = 400903493 is a prime.

It is a super-2 number, since 2×401427781² = 322288526717167922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (401427721) 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, 200713890 + 200713891.

It is an arithmetic number, because the mean of its divisors is an integer number (200713891).

Almost surely, 2^401427781 is an apocalyptic number.

It is an amenable number.

401427781 is a deficient number, since it is larger than the sum of its proper divisors (1).

401427781 is an equidigital number, since it uses as much as digits as its factorization.

401427781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12544, while the sum is 34.

The square root of 401427781 is about 20035.6627292436. The cubic root of 401427781 is about 737.6819237497.

The spelling of 401427781 in words is "four hundred one million, four hundred twenty-seven thousand, seven hundred eighty-one".