61215724860 has 96 divisors (see below), whose sum is σ = 176320972800. Its totient is φ = 15859253760.

The previous prime is 61215724811. The next prime is 61215724861. The reversal of 61215724860 is 6842751216.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61215724861) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 535881 + ... + 639999.

It is an arithmetic number, because the mean of its divisors is an integer number (1836676800).

Almost surely, 2^61215724860 is an apocalyptic number.

61215724860 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 61215724860, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (88160486400).

61215724860 is an abundant number, since it is smaller than the sum of its proper divisors (115105247940).

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

61215724860 is a wasteful number, since it uses less digits than its factorization.

61215724860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104411 (or 104409 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 42.

The spelling of 61215724860 in words is "sixty-one billion, two hundred fifteen million, seven hundred twenty-four thousand, eight hundred sixty".