647777520 has 640 divisors, whose sum is σ = 2699827200. Its totient is φ = 141115392.

The previous prime is 647777479. The next prime is 647777521. The reversal of 647777520 is 25777746.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647777521) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 10979251 + ... + 10979309.

It is an arithmetic number, because the mean of its divisors is an integer number (4218480).

Almost surely, 2^647777520 is an apocalyptic number.

647777520 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 647777520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1349913600).

647777520 is an abundant number, since it is smaller than the sum of its proper divisors (2052049680).

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

647777520 is a wasteful number, since it uses less digits than its factorization.

647777520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134 (or 122 counting only the distinct ones).

The product of its (nonzero) digits is 576240, while the sum is 45.

The square root of 647777520 is about 25451.4738276588. The cubic root of 647777520 is about 865.2506963778.

The spelling of 647777520 in words is "six hundred forty-seven million, seven hundred seventy-seven thousand, five hundred twenty".