61605520 has 20 divisors (see below), whose sum is σ = 143233020. Its totient is φ = 24642176.

The previous prime is 61605517. The next prime is 61605521. The reversal of 61605520 is 2550616.

It can be written as a sum of positive squares in 2 ways, for example, as 15147664 + 46457856 = 3892^2 + 6816^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is not an unprimeable number, because it can be changed into a prime (61605521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 384955 + ... + 385114.

It is an arithmetic number, because the mean of its divisors is an integer number (7161651).

Almost surely, 2^61605520 is an apocalyptic number.

It is an amenable number.

61605520 is an abundant number, since it is smaller than the sum of its proper divisors (81627500).

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

61605520 is a wasteful number, since it uses less digits than its factorization.

61605520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 770082 (or 770076 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 25.

The square root of 61605520 is about 7848.9183968239. The cubic root of 61605520 is about 394.9479608846.

The spelling of 61605520 in words is "sixty-one million, six hundred five thousand, five hundred twenty".