978845531 has 4 divisors (see below), whose sum is σ = 980496792. Its totient is φ = 977194272.

The previous prime is 978845519. The next prime is 978845537. The reversal of 978845531 is 135548879.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-978845531 is a prime.

It is a super-2 number, since 2×978845531² = 1916277147117343922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 978845531.

It is not an unprimeable number, because it can be changed into a prime (978845537) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 824741 + ... + 825926.

It is an arithmetic number, because the mean of its divisors is an integer number (245124198).

Almost surely, 2^978845531 is an apocalyptic number.

978845531 is a deficient number, since it is larger than the sum of its proper divisors (1651261).

978845531 is a wasteful number, since it uses less digits than its factorization.

978845531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1651260.

The product of its digits is 1209600, while the sum is 50.

The square root of 978845531 is about 31286.5071716227. The cubic root of 978845531 is about 992.8981940807.

The spelling of 978845531 in words is "nine hundred seventy-eight million, eight hundred forty-five thousand, five hundred thirty-one".