20015220 has 48 divisors (see below), whose sum is σ = 57980160. Its totient is φ = 5152896.

The previous prime is 20015207. The next prime is 20015231. The reversal of 20015220 is 2251002.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 20015196 and 20015205.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4012 + ... + 7491.

It is an arithmetic number, because the mean of its divisors is an integer number (1207920).

Almost surely, 2^20015220 is an apocalyptic number.

20015220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20015220 is an abundant number, since it is smaller than the sum of its proper divisors (37964940).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20015220 is a wasteful number, since it uses less digits than its factorization.

20015220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11544 (or 11542 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 12.

The square root of 20015220 is about 4473.8372791151. The cubic root of 20015220 is about 271.5105999273.

Adding to 20015220 its reverse (2251002), we get a palindrome (22266222).

The spelling of 20015220 in words is "twenty million, fifteen thousand, two hundred twenty".