196561994640 has 640 divisors, whose sum is σ = 714790821888. Its totient is φ = 44210749440.

The previous prime is 196561994633. The next prime is 196561994701. The reversal of 196561994640 is 46499165691.

It is a Harshad number since it is a multiple of its sum of digits (60).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 331470184 + ... + 331470776.

Almost surely, 2^196561994640 is an apocalyptic number.

196561994640 is a gapful number since it is divisible by the number (10) 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 196561994640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (357395410944).

196561994640 is an abundant number, since it is smaller than the sum of its proper divisors (518228827248).

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

196561994640 is a wasteful number, since it uses less digits than its factorization.

196561994640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 799 (or 793 counting only the distinct ones).

The product of its (nonzero) digits is 12597120, while the sum is 60.

The spelling of 196561994640 in words is "one hundred ninety-six billion, five hundred sixty-one million, nine hundred ninety-four thousand, six hundred forty".