378661 has 2 divisors, whose sum is σ = 378662. Its totient is φ = 378660.

The previous prime is 378629. The next prime is 378667. The reversal of 378661 is 166873.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 372100 + 6561 = 610^2 + 81^2 .

It is a cyclic number.

It is not a de Polignac number, because 378661 - 2⁵ = 378629 is a prime.

378661 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (378667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 189330 + 189331.

It is an arithmetic number, because the mean of its divisors is an integer number (189331).

2³⁷⁸⁶⁶¹ is an apocalyptic number.

It is an amenable number.

378661 is a deficient number, since it is larger than the sum of its proper divisors (1).

378661 is an equidigital number, since it uses as much as digits as its factorization.

378661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6048, while the sum is 31.

The square root of 378661 is about 615.3543694490. The cubic root of 378661 is about 72.3463889922.

The spelling of 378661 in words is "three hundred seventy-eight thousand, six hundred sixty-one".