61615620 has 288 divisors, whose sum is σ = 225227520. Its totient is φ = 13939200.

The previous prime is 61615573. The next prime is 61615663. The reversal of 61615620 is 2651616.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1502800 + ... + 1502840.

It is an arithmetic number, because the mean of its divisors is an integer number (782040).

Almost surely, 2^61615620 is an apocalyptic number.

61615620 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 61615620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (112613760).

61615620 is an abundant number, since it is smaller than the sum of its proper divisors (163611900).

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

61615620 is a wasteful number, since it uses less digits than its factorization.

61615620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104 (or 85 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 61615620 is about 7849.5617712074. The cubic root of 61615620 is about 394.9695431305.

It can be divided in two parts, 6161 and 5620, that added together give a triangular number (11781 = T₁₅₃).

The spelling of 61615620 in words is "sixty-one million, six hundred fifteen thousand, six hundred twenty".