61991193600 has 1782 divisors, whose sum is σ = 288712851180. Its totient is φ = 12634030080.

The previous prime is 61991193599. The next prime is 61991193637. The reversal of 61991193600 is 639119916.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 161 ways as a sum of consecutive naturals, for example, 3262694391 + ... + 3262694409.

Almost surely, 2^61991193600 is an apocalyptic number.

61991193600 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 61991193600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (144356425590).

61991193600 is an abundant number, since it is smaller than the sum of its proper divisors (226721657580).

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

61991193600 is a wasteful number, since it uses less digits than its factorization.

61991193600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103 (or 53 counting only the distinct ones).

The product of its (nonzero) digits is 78732, while the sum is 45.

The spelling of 61991193600 in words is "sixty-one billion, nine hundred ninety-one million, one hundred ninety-three thousand, six hundred".