61551920736 has 120 divisors (see below), whose sum is σ = 181170962280. Its totient is φ = 20500480512.

The previous prime is 61551920659. The next prime is 61551920767. The reversal of 61551920736 is 63702915516.

61551920736 is a `hidden beast` number, since 6 + 1 + 551 + 9 + 20 + 73 + 6 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 61551920691 and 61551920700.

It is a congruent number.

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 19 ways as a sum of consecutive naturals, for example, 3378660 + ... + 3396828.

It is an arithmetic number, because the mean of its divisors is an integer number (1509758019).

Almost surely, 2^61551920736 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61551920736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (90585481140).

61551920736 is an abundant number, since it is smaller than the sum of its proper divisors (119619041544).

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

61551920736 is a wasteful number, since it uses less digits than its factorization.

61551920736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19498 (or 19481 counting only the distinct ones).

The product of its (nonzero) digits is 340200, while the sum is 45.

The spelling of 61551920736 in words is "sixty-one billion, five hundred fifty-one million, nine hundred twenty thousand, seven hundred thirty-six".