20641515 has 16 divisors (see below), whose sum is σ = 33446400. Its totient is φ = 10868832.

The previous prime is 20641513. The next prime is 20641529. The reversal of 20641515 is 51514602.

It is not a de Polignac number, because 20641515 - 2¹ = 20641513 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20641513) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7525 + ... + 9894.

It is an arithmetic number, because the mean of its divisors is an integer number (2090400).

Almost surely, 2^20641515 is an apocalyptic number.

20641515 is a deficient number, since it is larger than the sum of its proper divisors (12804885).

20641515 is a wasteful number, since it uses less digits than its factorization.

20641515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17506.

The product of its (nonzero) digits is 1200, while the sum is 24.

The square root of 20641515 is about 4543.2934089711. The cubic root of 20641515 is about 274.3135053298.

The spelling of 20641515 in words is "twenty million, six hundred forty-one thousand, five hundred fifteen".