61605997740 has 576 divisors, whose sum is σ = 237895418880. Its totient is φ = 13150771200.

The previous prime is 61605997711. The next prime is 61605997753. The reversal of 61605997740 is 4779950616.

61605997740 is a `hidden beast` number, since 6 + 1 + 6 + 0 + 599 + 7 + 7 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 67922367 + ... + 67923273.

It is an arithmetic number, because the mean of its divisors is an integer number (413012880).

Almost surely, 2^61605997740 is an apocalyptic number.

61605997740 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 61605997740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (118947709440).

61605997740 is an abundant number, since it is smaller than the sum of its proper divisors (176289421140).

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

61605997740 is a wasteful number, since it uses less digits than its factorization.

61605997740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1107 (or 1092 counting only the distinct ones).

The product of its (nonzero) digits is 2857680, while the sum is 54.

The spelling of 61605997740 in words is "sixty-one billion, six hundred five million, nine hundred ninety-seven thousand, seven hundred forty".