20145515 has 8 divisors (see below), whose sum is σ = 26034288. Its totient is φ = 14876640.

The previous prime is 20145509. The next prime is 20145547. The reversal of 20145515 is 51554102.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20145515 - 2¹⁸ = 19883371 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 154901 + ... + 155030.

It is an arithmetic number, because the mean of its divisors is an integer number (3254286).

Almost surely, 2^20145515 is an apocalyptic number.

20145515 is a deficient number, since it is larger than the sum of its proper divisors (5888773).

20145515 is a wasteful number, since it uses less digits than its factorization.

20145515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 309949.

The product of its (nonzero) digits is 1000, while the sum is 23.

The square root of 20145515 is about 4488.3755413290. The cubic root of 20145515 is about 272.0984856380.

Adding to 20145515 its reverse (51554102), we get a palindrome (71699617).

The spelling of 20145515 in words is "twenty million, one hundred forty-five thousand, five hundred fifteen".