20091915 has 16 divisors (see below), whose sum is σ = 35719200. Its totient is φ = 10715616.

The previous prime is 20091913. The next prime is 20091923. The reversal of 20091915 is 51919002.

It is a happy number.

It is not a de Polignac number, because 20091915 - 2¹ = 20091913 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (20091913) 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, 74280 + ... + 74549.

It is an arithmetic number, because the mean of its divisors is an integer number (2232450).

Almost surely, 2^20091915 is an apocalyptic number.

20091915 is a deficient number, since it is larger than the sum of its proper divisors (15627285).

20091915 is a wasteful number, since it uses less digits than its factorization.

20091915 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 148843 (or 148837 counting only the distinct ones).

The product of its (nonzero) digits is 810, while the sum is 27.

The square root of 20091915 is about 4482.4005845083. The cubic root of 20091915 is about 271.8569524286.

The spelling of 20091915 in words is "twenty million, ninety-one thousand, nine hundred fifteen".