381221822257 has 4 divisors (see below), whose sum is σ = 381223059316. Its totient is φ = 381220585200.

The previous prime is 381221822243. The next prime is 381221822279. The reversal of 381221822257 is 752228122183.

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, and also an emirpimes, since its reverse is a distinct semiprime: 752228122183 = 188983 ⋅3980401.

It can be written as a sum of positive squares in 2 ways, for example, as 123605683776 + 257616138481 = 351576^2 + 507559^2 .

It is a cyclic number.

It is not a de Polignac number, because 381221822257 - 2¹⁹ = 381221297969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (381221822237) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 254023 + ... + 909379.

It is an arithmetic number, because the mean of its divisors is an integer number (95305764829).

Almost surely, 2^381221822257 is an apocalyptic number.

It is an amenable number.

381221822257 is a deficient number, since it is larger than the sum of its proper divisors (1237059).

381221822257 is an equidigital number, since it uses as much as digits as its factorization.

381221822257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1237058.

The product of its digits is 215040, while the sum is 43.

The spelling of 381221822257 in words is "three hundred eighty-one billion, two hundred twenty-one million, eight hundred twenty-two thousand, two hundred fifty-seven".