661096035840 has 320 divisors, whose sum is σ = 2168357216256. Its totient is φ = 171770314752.

The previous prime is 661096035839. The next prime is 661096035973. The reversal of 661096035840 is 48530690166.

It is a tau number, because it is divible by the number of its divisors (320).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 661096035840.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 46526017 + ... + 46540223.

Almost surely, 2^661096035840 is an apocalyptic number.

661096035840 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 661096035840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1084178608128).

661096035840 is an abundant number, since it is smaller than the sum of its proper divisors (1507261180416).

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

661096035840 is a wasteful number, since it uses less digits than its factorization.

661096035840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14389 (or 14373 counting only the distinct ones).

The product of its (nonzero) digits is 933120, while the sum is 48.

The spelling of 661096035840 in words is "six hundred sixty-one billion, ninety-six million, thirty-five thousand, eight hundred forty".