978478957 has 2 divisors, whose sum is σ = 978478958. Its totient is φ = 978478956.

The previous prime is 978478931. The next prime is 978478973. The reversal of 978478957 is 759874879.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 685863721 + 292615236 = 26189^2 + 17106^2 .

It is an emirp because it is prime and its reverse (759874879) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 978478957 - 2¹⁹ = 977954669 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (978488957) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 489239478 + 489239479.

It is an arithmetic number, because the mean of its divisors is an integer number (489239479).

Almost surely, 2^978478957 is an apocalyptic number.

It is an amenable number.

978478957 is a deficient number, since it is larger than the sum of its proper divisors (1).

978478957 is an equidigital number, since it uses as much as digits as its factorization.

978478957 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 35562240, while the sum is 64.

The square root of 978478957 is about 31280.6482829241. The cubic root of 978478957 is about 992.7742330485.

The spelling of 978478957 in words is "nine hundred seventy-eight million, four hundred seventy-eight thousand, nine hundred fifty-seven".