61920 has 72 divisors (see below), whose sum is σ = 216216. Its totient is φ = 16128.

The previous prime is 61909. The next prime is 61927. The reversal of 61920 is 2916.

61920 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 (72).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a zygodrome in base 2.

It is a junction number, because it is equal to n+sod(n) for n = 61893 and 61902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61927) by changing a digit.

61920 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1419 + ... + 1461.

It is an arithmetic number, because the mean of its divisors is an integer number (3003).

2⁶¹⁹²⁰ is an apocalyptic number.

61920 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

61920 is the 144-th octagonal number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (108108).

61920 is an abundant number, since it is smaller than the sum of its proper divisors (154296).

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

61920 is a wasteful number, since it uses less digits than its factorization.

61920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64 (or 53 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 18.

The square root of 61920 is about 248.8372962399. The cubic root of 61920 is about 39.5618855800.

The spelling of 61920 in words is "sixty-one thousand, nine hundred twenty".