401987942381 has 2 divisors, whose sum is σ = 401987942382. Its totient is φ = 401987942380.

The previous prime is 401987942351. The next prime is 401987942417. The reversal of 401987942381 is 183249789104.

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., 401898942025 + 89000356 = 633955^2 + 9434^2 .

It is a cyclic number.

It is not a de Polignac number, because 401987942381 - 2³⁴ = 384808073197 is a prime.

It is a super-2 number, since 2×401987942381² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (401987942311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200993971190 + 200993971191.

It is an arithmetic number, because the mean of its divisors is an integer number (200993971191).

Almost surely, 2^401987942381 is an apocalyptic number.

It is an amenable number.

401987942381 is a deficient number, since it is larger than the sum of its proper divisors (1).

401987942381 is an equidigital number, since it uses as much as digits as its factorization.

401987942381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3483648, while the sum is 56.

The spelling of 401987942381 in words is "four hundred one billion, nine hundred eighty-seven million, nine hundred forty-two thousand, three hundred eighty-one".