978487261 has 4 divisors (see below), whose sum is σ = 979715772. Its totient is φ = 977258752.

The previous prime is 978487253. The next prime is 978487273. The reversal of 978487261 is 162784879.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 162784879 = 229 ⋅710851.

It can be written as a sum of positive squares in 2 ways, for example, as 825470361 + 153016900 = 28731^2 + 12370^2 .

It is a cyclic number.

It is not a de Polignac number, because 978487261 - 2³ = 978487253 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 978487199 and 978487208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (978487201) 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 in 3 ways as a sum of consecutive naturals, for example, 613060 + ... + 614653.

It is an arithmetic number, because the mean of its divisors is an integer number (244928943).

Almost surely, 2^978487261 is an apocalyptic number.

It is an amenable number.

978487261 is a deficient number, since it is larger than the sum of its proper divisors (1228511).

978487261 is a wasteful number, since it uses less digits than its factorization.

978487261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1228510.

The product of its digits is 1354752, while the sum is 52.

The square root of 978487261 is about 31280.7810164644. The cubic root of 978487261 is about 992.7770414802. Note that the first 3 decimals are identical.

The spelling of 978487261 in words is "nine hundred seventy-eight million, four hundred eighty-seven thousand, two hundred sixty-one".