381779581 has 2 divisors, whose sum is σ = 381779582. Its totient is φ = 381779580.

The previous prime is 381779537. The next prime is 381779603. The reversal of 381779581 is 185977183.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 270898681 + 110880900 = 16459^2 + 10530^2 .

It is a cyclic number.

It is not a de Polignac number, because 381779581 - 2¹⁹ = 381255293 is a prime.

It is a super-2 number, since 2×381779581² = 291511296937071122, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (381779381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 190889790 + 190889791.

It is an arithmetic number, because the mean of its divisors is an integer number (190889791).

Almost surely, 2^381779581 is an apocalyptic number.

It is an amenable number.

381779581 is a deficient number, since it is larger than the sum of its proper divisors (1).

381779581 is an equidigital number, since it uses as much as digits as its factorization.

381779581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 423360, while the sum is 49.

The square root of 381779581 is about 19539.1806634772. The cubic root of 381779581 is about 725.4445666563. Note that the first 3 decimals are identical.

The spelling of 381779581 in words is "three hundred eighty-one million, seven hundred seventy-nine thousand, five hundred eighty-one".