61520724720 has 1800 divisors, whose sum is σ = 294835441824. Its totient is φ = 11573673984.

The previous prime is 61520724719. The next prime is 61520724757. The reversal of 61520724720 is 2742702516.

It is a happy number.

61520724720 is a `hidden beast` number, since 6 + 1 + 520 + 72 + 47 + 20 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 359 ways as a sum of consecutive naturals, for example, 3237932871 + ... + 3237932889.

Almost surely, 2^61520724720 is an apocalyptic number.

61520724720 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 61520724720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (147417720912).

61520724720 is an abundant number, since it is smaller than the sum of its proper divisors (233314717104).

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

61520724720 is a wasteful number, since it uses less digits than its factorization.

61520724720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117 (or 66 counting only the distinct ones).

The product of its (nonzero) digits is 47040, while the sum is 36.

The spelling of 61520724720 in words is "sixty-one billion, five hundred twenty million, seven hundred twenty-four thousand, seven hundred twenty".