20615 has 16 divisors (see below), whose sum is σ = 30720. Its totient is φ = 12960.

The previous prime is 20611. The next prime is 20627. The reversal of 20615 is 51602.

20615 is nontrivially palindromic in base 11.

It is not a de Polignac number, because 20615 - 2² = 20611 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20615.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20611) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 650 + ... + 680.

It is an arithmetic number, because the mean of its divisors is an integer number (1920).

2²⁰⁶¹⁵ is an apocalyptic number.

20615 is a deficient number, since it is larger than the sum of its proper divisors (10105).

20615 is a wasteful number, since it uses less digits than its factorization.

20615 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62.

The product of its (nonzero) digits is 60, while the sum is 14.

The square root of 20615 is about 143.5792464112. The cubic root of 20615 is about 27.4195998787.

The spelling of 20615 in words is "twenty thousand, six hundred fifteen".