378771721 has 2 divisors, whose sum is σ = 378771722. Its totient is φ = 378771720.

The previous prime is 378771683. The next prime is 378771727. The reversal of 378771721 is 127177873.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 284293321 + 94478400 = 16861^2 + 9720^2 .

It is an emirp because it is prime and its reverse (127177873) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 378771721 - 2²¹ = 376674569 is a prime.

It is not a weakly prime, because it can be changed into another prime (378771727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 189385860 + 189385861.

It is an arithmetic number, because the mean of its divisors is an integer number (189385861).

Almost surely, 2^378771721 is an apocalyptic number.

It is an amenable number.

378771721 is a deficient number, since it is larger than the sum of its proper divisors (1).

378771721 is an equidigital number, since it uses as much as digits as its factorization.

378771721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 115248, while the sum is 43.

The square root of 378771721 is about 19462.0584985248. The cubic root of 378771721 is about 723.5343969973.

The spelling of 378771721 in words is "three hundred seventy-eight million, seven hundred seventy-one thousand, seven hundred twenty-one".