20015915 has 16 divisors (see below), whose sum is σ = 24602400. Its totient is φ = 15628800.

The previous prime is 20015909. The next prime is 20015917. The reversal of 20015915 is 51951002.

It is not a de Polignac number, because 20015915 - 2⁴ = 20015899 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20015917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 49715 + ... + 50115.

It is an arithmetic number, because the mean of its divisors is an integer number (1537650).

Almost surely, 2^20015915 is an apocalyptic number.

20015915 is a deficient number, since it is larger than the sum of its proper divisors (4586485).

20015915 is a wasteful number, since it uses less digits than its factorization.

20015915 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 622.

The product of its (nonzero) digits is 450, while the sum is 23.

The square root of 20015915 is about 4473.9149522538. The cubic root of 20015915 is about 271.5137424972.

Adding to 20015915 its reverse (51951002), we get a palindrome (71966917).

The spelling of 20015915 in words is "twenty million, fifteen thousand, nine hundred fifteen".