1220129215 has 4 divisors (see below), whose sum is σ = 1464155064. Its totient is φ = 976103368.

The previous prime is 1220129203. The next prime is 1220129269. The reversal of 1220129215 is 5129210221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5129210221 = 4139 ⋅1239239.

It is a cyclic number.

It is not a de Polignac number, because 1220129215 - 2⁷ = 1220129087 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1220129215.

It is a congruent 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, 122012917 + ... + 122012926.

It is an arithmetic number, because the mean of its divisors is an integer number (366038766).

Almost surely, 2^1220129215 is an apocalyptic number.

1220129215 is a deficient number, since it is larger than the sum of its proper divisors (244025849).

1220129215 is an equidigital number, since it uses as much as digits as its factorization.

1220129215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 244025848.

The product of its (nonzero) digits is 720, while the sum is 25.

The square root of 1220129215 is about 34930.3480515153. The cubic root of 1220129215 is about 1068.5674528797.

Adding to 1220129215 its reverse (5129210221), we get a palindrome (6349339436).

The spelling of 1220129215 in words is "one billion, two hundred twenty million, one hundred twenty-nine thousand, two hundred fifteen".