80865945 has 20 divisors (see below), whose sum is σ = 144960420. Its totient is φ = 43128288.

The previous prime is 80865877. The next prime is 80865971. The reversal of 80865945 is 54956808.

It can be written as a sum of positive squares in 2 ways, for example, as 41062464 + 39803481 = 6408^2 + 6309^2 .

It is not a de Polignac number, because 80865945 - 2¹¹ = 80863897 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 80865945.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 99430 + ... + 100239.

It is an arithmetic number, because the mean of its divisors is an integer number (7248021).

Almost surely, 2^80865945 is an apocalyptic number.

It is an amenable number.

80865945 is a deficient number, since it is larger than the sum of its proper divisors (64094475).

80865945 is a wasteful number, since it uses less digits than its factorization.

80865945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199686 (or 199677 counting only the distinct ones).

The product of its (nonzero) digits is 345600, while the sum is 45.

The square root of 80865945 is about 8992.5494160444. The cubic root of 80865945 is about 432.4360469885.

It can be divided in two parts, 80865 and 945, that added together give a triangular number (81810 = T₄₀₄).

The spelling of 80865945 in words is "eighty million, eight hundred sixty-five thousand, nine hundred forty-five".