661616429760 has 672 divisors, whose sum is σ = 2691490314240. Its totient is φ = 147059712000.

The previous prime is 661616429737. The next prime is 661616429777. The reversal of 661616429760 is 67924616166.

661616429760 is a `hidden beast` number, since 6 + 616 + 16 + 4 + 2 + 9 + 7 + 6 + 0 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 661616429697 and 661616429706.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 62182521 + ... + 62193159.

It is an arithmetic number, because the mean of its divisors is an integer number (4005193920).

Almost surely, 2^661616429760 is an apocalyptic number.

661616429760 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 661616429760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1345745157120).

661616429760 is an abundant number, since it is smaller than the sum of its proper divisors (2029873884480).

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

661616429760 is a wasteful number, since it uses less digits than its factorization.

661616429760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10837 (or 10824 counting only the distinct ones).

The product of its (nonzero) digits is 3919104, while the sum is 54.

The spelling of 661616429760 in words is "six hundred sixty-one billion, six hundred sixteen million, four hundred twenty-nine thousand, seven hundred sixty".