61905220 has 48 divisors (see below), whose sum is σ = 140576688. Its totient is φ = 22763520.

The previous prime is 61905197. The next prime is 61905289. The reversal of 61905220 is 2250916.

It can be written as a sum of positive squares in 8 ways, for example, as 1811716 + 60093504 = 1346^2 + 7752^2 .

It is a nialpdrome in base 13.

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 15 ways as a sum of consecutive naturals, for example, 118560 + ... + 119080.

It is an arithmetic number, because the mean of its divisors is an integer number (2928681).

Almost surely, 2^61905220 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 61905220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (70288344).

61905220 is an abundant number, since it is smaller than the sum of its proper divisors (78671468).

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

61905220 is a wasteful number, since it uses less digits than its factorization.

61905220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1000 (or 998 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 61905220 is about 7867.9870360849. The cubic root of 61905220 is about 395.5873758693.

The spelling of 61905220 in words is "sixty-one million, nine hundred five thousand, two hundred twenty".