61515 has 12 divisors (see below), whose sum is σ = 106704. Its totient is φ = 32784.

The previous prime is 61511. The next prime is 61519. The reversal of 61515 is 51516.

61515 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (61511) and next prime (61519).

It is not a de Polignac number, because 61515 - 2² = 61511 is a prime.

It is not an unprimeable number, because it can be changed into a prime (61511) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 639 + ... + 728.

It is an arithmetic number, because the mean of its divisors is an integer number (8892).

2⁶¹⁵¹⁵ is an apocalyptic number.

61515 is a deficient number, since it is larger than the sum of its proper divisors (45189).

61515 is a wasteful number, since it uses less digits than its factorization.

61515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1378 (or 1375 counting only the distinct ones).

The product of its digits is 150, while the sum is 18.

The square root of 61515 is about 248.0221764278. The cubic root of 61515 is about 39.4754427287.

Subtracting from 61515 its reverse (51516), we obtain a palindrome (9999).

It can be divided in two parts, 615 and 15, that added together give a triangular number (630 = T₃₅).

The spelling of 61515 in words is "sixty-one thousand, five hundred fifteen".