61115880 has 128 divisors (see below), whose sum is σ = 216391680. Its totient is φ = 13512960.

The previous prime is 61115869. The next prime is 61115893. The reversal of 61115880 is 8851116.

It is a happy number.

61115880 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 24867 + ... + 27213.

It is an arithmetic number, because the mean of its divisors is an integer number (1690560).

Almost surely, 2^61115880 is an apocalyptic number.

61115880 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 61115880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (108195840).

61115880 is an abundant number, since it is smaller than the sum of its proper divisors (155275800).

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

61115880 is a wasteful number, since it uses less digits than its factorization.

61115880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2399 (or 2395 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 30.

The square root of 61115880 is about 7817.6646129135. The cubic root of 61115880 is about 393.8988291002.

Adding to 61115880 its reverse (8851116), we get a palindrome (69966996).

The spelling of 61115880 in words is "sixty-one million, one hundred fifteen thousand, eight hundred eighty".