645768777600 has 288 divisors, whose sum is σ = 2425529410200. Its totient is φ = 163141447680.

The previous prime is 645768777557. The next prime is 645768777623. The reversal of 645768777600 is 6777867546.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (288).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 42867 + ... + 1137266.

Almost surely, 2^645768777600 is an apocalyptic number.

645768777600 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645768777600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1212764705100).

645768777600 is an abundant number, since it is smaller than the sum of its proper divisors (1779760632600).

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

645768777600 is a wasteful number, since it uses less digits than its factorization.

645768777600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1180182 (or 1180162 counting only the distinct ones).

The product of its (nonzero) digits is 82978560, while the sum is 63.

The spelling of 645768777600 in words is "six hundred forty-five billion, seven hundred sixty-eight million, seven hundred seventy-seven thousand, six hundred".