666731520 has 704 divisors, whose sum is σ = 2971261440. Its totient is φ = 138018816.

The previous prime is 666731491. The next prime is 666731543. The reversal of 666731520 is 25137666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 12579814 + ... + 12579866.

Almost surely, 2^666731520 is an apocalyptic number.

666731520 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 666731520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1485630720).

666731520 is an abundant number, since it is smaller than the sum of its proper divisors (2304529920).

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

666731520 is a wasteful number, since it uses less digits than its factorization.

666731520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107 (or 83 counting only the distinct ones).

The product of its (nonzero) digits is 45360, while the sum is 36.

The square root of 666731520 is about 25821.1448235743. The cubic root of 666731520 is about 873.6087911203.

The spelling of 666731520 in words is "six hundred sixty-six million, seven hundred thirty-one thousand, five hundred twenty".