1220505515 has 4 divisors (see below), whose sum is σ = 1464606624. Its totient is φ = 976404408.

The previous prime is 1220505509. The next prime is 1220505521. The reversal of 1220505515 is 5155050221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5155050221 = 33529 ⋅153749.

It is an interprime number because it is at equal distance from previous prime (1220505509) and next prime (1220505521).

It is a cyclic number.

It is not a de Polignac number, because 1220505515 - 2⁴ = 1220505499 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 122050547 + ... + 122050556.

It is an arithmetic number, because the mean of its divisors is an integer number (366151656).

Almost surely, 2^1220505515 is an apocalyptic number.

1220505515 is a deficient number, since it is larger than the sum of its proper divisors (244101109).

1220505515 is an equidigital number, since it uses as much as digits as its factorization.

1220505515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 244101108.

The product of its (nonzero) digits is 2500, while the sum is 26.

The square root of 1220505515 is about 34935.7340698603. The cubic root of 1220505515 is about 1068.6772938696.

Adding to 1220505515 its reverse (5155050221), we get a palindrome (6375555736).

The spelling of 1220505515 in words is "one billion, two hundred twenty million, five hundred five thousand, five hundred fifteen".