381652661 has 16 divisors (see below), whose sum is σ = 419691888. Its totient is φ = 344908800.

The previous prime is 381652637. The next prime is 381652693. The reversal of 381652661 is 166256183.

It can be written as a sum of positive squares in 8 ways, for example, as 150430225 + 231222436 = 12265^2 + 15206^2 .

It is a cyclic number.

It is not a de Polignac number, because 381652661 - 2²⁶ = 314543797 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (381652861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 190115 + ... + 192111.

It is an arithmetic number, because the mean of its divisors is an integer number (26230743).

Almost surely, 2^381652661 is an apocalyptic number.

It is an amenable number.

381652661 is a deficient number, since it is larger than the sum of its proper divisors (38039227).

381652661 is a wasteful number, since it uses less digits than its factorization.

381652661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2312.

The product of its digits is 51840, while the sum is 38.

The square root of 381652661 is about 19535.9325602849. The cubic root of 381652661 is about 725.3641680582.

The spelling of 381652661 in words is "three hundred eighty-one million, six hundred fifty-two thousand, six hundred sixty-one".