61611920 has 40 divisors (see below), whose sum is σ = 144365760. Its totient is φ = 24452480.

The previous prime is 61611839. The next prime is 61611937. The reversal of 61611920 is 2911616.

61611920 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (40).

It is a self number, because there is not a number n which added to its sum of digits gives 61611920.

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 7 ways as a sum of consecutive naturals, for example, 7541 + ... + 13419.

It is an arithmetic number, because the mean of its divisors is an integer number (3609144).

Almost surely, 2^61611920 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 61611920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (72182880).

61611920 is an abundant number, since it is smaller than the sum of its proper divisors (82753840).

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

61611920 is a wasteful number, since it uses less digits than its factorization.

61611920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6023 (or 6017 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 26.

The square root of 61611920 is about 7849.3260857223. The cubic root of 61611920 is about 394.9616370370.

The spelling of 61611920 in words is "sixty-one million, six hundred eleven thousand, nine hundred twenty".