1500220021 has 4 divisors (see below), whose sum is σ = 1503100044. Its totient is φ = 1497340000.

The previous prime is 1500220013. The next prime is 1500220037. The reversal of 1500220021 is 1200220051.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1200220051 = 227 ⋅5287313.

It can be written as a sum of positive squares in 2 ways, for example, as 905347921 + 594872100 = 30089^2 + 24390^2 .

It is a cyclic number.

It is not a de Polignac number, because 1500220021 - 2³ = 1500220013 is a prime.

It is a super-2 number, since 2×1500220021² = 4501320222818480882, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1500219983 and 1500220010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1500220061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1439230 + ... + 1440271.

It is an arithmetic number, because the mean of its divisors is an integer number (375775011).

Almost surely, 2^1500220021 is an apocalyptic number.

It is an amenable number.

1500220021 is a deficient number, since it is larger than the sum of its proper divisors (2880023).

1500220021 is an equidigital number, since it uses as much as digits as its factorization.

1500220021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2880022.

The product of its (nonzero) digits is 40, while the sum is 13.

The square root of 1500220021 is about 38732.6738168178. The cubic root of 1500220021 is about 1144.7702089664.

Adding to 1500220021 its reverse (1200220051), we get a palindrome (2700440072).

The spelling of 1500220021 in words is "one billion, five hundred million, two hundred twenty thousand, twenty-one".