1221244015 has 16 divisors (see below), whose sum is σ = 1524170880. Its totient is φ = 938545920.

The previous prime is 1221244007. The next prime is 1221244021. The reversal of 1221244015 is 5104421221.

It is not a de Polignac number, because 1221244015 - 2³ = 1221244007 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27166 + ... + 56395.

It is an arithmetic number, because the mean of its divisors is an integer number (95260680).

Almost surely, 2^1221244015 is an apocalyptic number.

1221244015 is a deficient number, since it is larger than the sum of its proper divisors (302926865).

1221244015 is an equidigital number, since it uses as much as digits as its factorization.

1221244015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83682.

The product of its (nonzero) digits is 640, while the sum is 22.

The square root of 1221244015 is about 34946.3018787396. The cubic root of 1221244015 is about 1068.8927944814.

Adding to 1221244015 its reverse (5104421221), we get a palindrome (6325665236).

The spelling of 1221244015 in words is "one billion, two hundred twenty-one million, two hundred forty-four thousand, fifteen".