381840856421 has 2 divisors, whose sum is σ = 381840856422. Its totient is φ = 381840856420.

The previous prime is 381840856409. The next prime is 381840856469. The reversal of 381840856421 is 124658048183.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 305753702500 + 76087153921 = 552950^2 + 275839^2 .

It is a cyclic number.

It is not a de Polignac number, because 381840856421 - 2⁶ = 381840856357 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 381840856421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (381840856471) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 190920428210 + 190920428211.

It is an arithmetic number, because the mean of its divisors is an integer number (190920428211).

Almost surely, 2^381840856421 is an apocalyptic number.

It is an amenable number.

381840856421 is a deficient number, since it is larger than the sum of its proper divisors (1).

381840856421 is an equidigital number, since it uses as much as digits as its factorization.

381840856421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1474560, while the sum is 50.

The spelling of 381840856421 in words is "three hundred eighty-one billion, eight hundred forty million, eight hundred fifty-six thousand, four hundred twenty-one".