278160661 has 2 divisors, whose sum is σ = 278160662. Its totient is φ = 278160660.

The previous prime is 278160601. The next prime is 278160691. The reversal of 278160661 is 166061872.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 235008900 + 43151761 = 15330^2 + 6569^2 .

It is a cyclic number.

It is not a de Polignac number, because 278160661 - 2²¹ = 276063509 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 278160661.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (278160601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 139080330 + 139080331.

It is an arithmetic number, because the mean of its divisors is an integer number (139080331).

Almost surely, 2^278160661 is an apocalyptic number.

It is an amenable number.

278160661 is a deficient number, since it is larger than the sum of its proper divisors (1).

278160661 is an equidigital number, since it uses as much as digits as its factorization.

278160661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24192, while the sum is 37.

The square root of 278160661 is about 16678.1492078708. The cubic root of 278160661 is about 652.7775899873. Note that the first 3 decimals are identical.

The spelling of 278160661 in words is "two hundred seventy-eight million, one hundred sixty thousand, six hundred sixty-one".