61505 has 4 divisors (see below), whose sum is σ = 73812. Its totient is φ = 49200.

The previous prime is 61493. The next prime is 61507. The reversal of 61505 is 50516.

It is a Cunningham number, because it is equal to 248²+1.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 21904 + 39601 = 148^2 + 199^2 .

It is not a de Polignac number, because 61505 - 2⁶ = 61441 is a prime.

It is a Duffinian number.

It is a plaindrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (61507) 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, 6146 + ... + 6155.

It is an arithmetic number, because the mean of its divisors is an integer number (18453).

2⁶¹⁵⁰⁵ is an apocalyptic number.

It is an amenable number.

61505 is a deficient number, since it is larger than the sum of its proper divisors (12307).

61505 is a wasteful number, since it uses less digits than its factorization.

61505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12306.

The product of its (nonzero) digits is 150, while the sum is 17.

The square root of 61505 is about 248.0020161208. The cubic root of 61505 is about 39.4733035441.

The spelling of 61505 in words is "sixty-one thousand, five hundred five".