20215355 has 4 divisors (see below), whose sum is σ = 24258432. Its totient is φ = 16172280.

The previous prime is 20215343. The next prime is 20215381. The reversal of 20215355 is 55351202.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 20215355 - 2⁸ = 20215099 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20215355.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2021531 + ... + 2021540.

It is an arithmetic number, because the mean of its divisors is an integer number (6064608).

Almost surely, 2^20215355 is an apocalyptic number.

20215355 is a deficient number, since it is larger than the sum of its proper divisors (4043077).

20215355 is an equidigital number, since it uses as much as digits as its factorization.

20215355 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4043076.

The product of its (nonzero) digits is 1500, while the sum is 23.

The square root of 20215355 is about 4496.1489076764. The cubic root of 20215355 is about 272.4125578653.

Adding to 20215355 its reverse (55351202), we get a palindrome (75566557).

The spelling of 20215355 in words is "twenty million, two hundred fifteen thousand, three hundred fifty-five".