661594537296 has 480 divisors, whose sum is σ = 2376875584512. Its totient is φ = 166797066240.

The previous prime is 661594537273. The next prime is 661594537297. The reversal of 661594537296 is 692735495166.

661594537296 is a `hidden beast` number, since 6 + 6 + 1 + 5 + 9 + 4 + 537 + 2 + 96 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661594537297) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 77711536 + ... + 77720048.

Almost surely, 2^661594537296 is an apocalyptic number.

661594537296 is a gapful number since it is divisible by the number (66) 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 661594537296, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1188437792256).

661594537296 is an abundant number, since it is smaller than the sum of its proper divisors (1715281047216).

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

661594537296 is a wasteful number, since it uses less digits than its factorization.

661594537296 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8751 (or 8742 counting only the distinct ones).

The product of its digits is 73483200, while the sum is 63.

The spelling of 661594537296 in words is "six hundred sixty-one billion, five hundred ninety-four million, five hundred thirty-seven thousand, two hundred ninety-six".