1515221249 has 4 divisors (see below), whose sum is σ = 1515300564. Its totient is φ = 1515141936.

The previous prime is 1515221243. The next prime is 1515221269. The reversal of 1515221249 is 9421225151.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 780811249 + 734410000 = 27943^2 + 27100^2 .

It is a cyclic number.

It is not a de Polignac number, because 1515221249 - 2¹² = 1515217153 is a prime.

It is a super-2 number, since 2×1515221249² = 4591790866842240002, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1515221243) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 8459 + ... + 55695.

It is an arithmetic number, because the mean of its divisors is an integer number (378825141).

Almost surely, 2^1515221249 is an apocalyptic number.

It is an amenable number.

1515221249 is a deficient number, since it is larger than the sum of its proper divisors (79315).

1515221249 is an equidigital number, since it uses as much as digits as its factorization.

1515221249 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79314.

The product of its digits is 7200, while the sum is 32.

The square root of 1515221249 is about 38925.8429452722. The cubic root of 1515221249 is about 1148.5732145386.

The spelling of 1515221249 in words is "one billion, five hundred fifteen million, two hundred twenty-one thousand, two hundred forty-nine".