645680080 has 40 divisors (see below), whose sum is σ = 1502752032. Its totient is φ = 258006144.

The previous prime is 645680071. The next prime is 645680089. The reversal of 645680080 is 80086546.

645680080 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

645680080 is a nontrivial binomial coefficient, being equal to C(35936, 2).

It is an interprime number because it is at equal distance from previous prime (645680071) and next prime (645680089).

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-3 number, since 3×645680080³ (a number of 27 digits) contains 333 as substring.

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645680089) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 86247 + ... + 93433.

Almost surely, 2^645680080 is an apocalyptic number.

645680080 is the 35935-th triangular number and also the 17968-th hexagonal number.

645680080 is the 11979-th centered nonagonal number.

It is an amenable number.

645680080 is an abundant number, since it is smaller than the sum of its proper divisors (857071952).

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

645680080 is a wasteful number, since it uses less digits than its factorization.

645680080 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8323 (or 8317 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 37.

The square root of 645680080 is about 25410.2357328695. The cubic root of 645680080 is about 864.3158210425.

The spelling of 645680080 in words is "six hundred forty-five million, six hundred eighty thousand, eighty".