661593744 has 320 divisors, whose sum is σ = 2287393280. Its totient is φ = 181398528.

The previous prime is 661593719. The next prime is 661593773. The reversal of 661593744 is 447395166.

It is a self number, because there is not a number n which added to its sum of digits gives 661593744.

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, 9062892 + ... + 9062964.

It is an arithmetic number, because the mean of its divisors is an integer number (7148104).

Almost surely, 2^661593744 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 661593744, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1143696640).

661593744 is an abundant number, since it is smaller than the sum of its proper divisors (1625799536).

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

661593744 is an equidigital number, since it uses as much as digits as its factorization.

661593744 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146 (or 122 counting only the distinct ones).

The product of its digits is 544320, while the sum is 45.

The square root of 661593744 is about 25721.4646550308. The cubic root of 661593744 is about 871.3590174865.

The spelling of 661593744 in words is "six hundred sixty-one million, five hundred ninety-three thousand, seven hundred forty-four".