20213015 has 4 divisors (see below), whose sum is σ = 24255624. Its totient is φ = 16170408.

The previous prime is 20212991. The next prime is 20213047. The reversal of 20213015 is 51031202.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 20213015 - 2¹⁸ = 19950871 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 2021297 + ... + 2021306.

It is an arithmetic number, because the mean of its divisors is an integer number (6063906).

Almost surely, 2^20213015 is an apocalyptic number.

20213015 is a deficient number, since it is larger than the sum of its proper divisors (4042609).

20213015 is an equidigital number, since it uses as much as digits as its factorization.

20213015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4042608.

The product of its (nonzero) digits is 60, while the sum is 14.

The square root of 20213015 is about 4495.8886774474. Note that the first 3 decimals coincide. The cubic root of 20213015 is about 272.4020465488.

Adding to 20213015 its reverse (51031202), we get a palindrome (71244217).

The spelling of 20213015 in words is "twenty million, two hundred thirteen thousand, fifteen".