80945640 has 192 divisors, whose sum is σ = 277430400. Its totient is φ = 20445696.

The previous prime is 80945617. The next prime is 80945647. The reversal of 80945640 is 4654908.

80945640 = 835² + 836² + ... + 937².

80945640 is a `hidden beast` number, since 8 + 0 + 9 + 4 + 5 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 80945595 and 80945604.

It is not an unprimeable number, because it can be changed into a prime (80945647) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 785829 + ... + 785931.

It is an arithmetic number, because the mean of its divisors is an integer number (1444950).

Almost surely, 2^80945640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 80945640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (138715200).

80945640 is an abundant number, since it is smaller than the sum of its proper divisors (196484760).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

80945640 is a wasteful number, since it uses less digits than its factorization.

80945640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 216 (or 209 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 80945640 is about 8996.9794931410. The cubic root of 80945640 is about 432.5780584605.

The spelling of 80945640 in words is "eighty million, nine hundred forty-five thousand, six hundred forty".