1501223221 has 4 divisors (see below), whose sum is σ = 1505476332. Its totient is φ = 1496970112.

The previous prime is 1501223177. The next prime is 1501223257. The reversal of 1501223221 is 1223221051.

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

It can be written as a sum of positive squares in 2 ways, for example, as 489028996 + 1012194225 = 22114^2 + 31815^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1501223221 is a prime.

It is a super-2 number, since 2×1501223221² = 4507342318539229682, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1501223261) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2126026 + ... + 2126731.

It is an arithmetic number, because the mean of its divisors is an integer number (376369083).

Almost surely, 2^1501223221 is an apocalyptic number.

It is an amenable number.

1501223221 is a deficient number, since it is larger than the sum of its proper divisors (4253111).

1501223221 is an equidigital number, since it uses as much as digits as its factorization.

1501223221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4253110.

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 1501223221 is about 38745.6219591324. The cubic root of 1501223221 is about 1145.0253221201.

Adding to 1501223221 its reverse (1223221051), we get a palindrome (2724444272).

The spelling of 1501223221 in words is "one billion, five hundred one million, two hundred twenty-three thousand, two hundred twenty-one".