1221235715 has 64 divisors (see below), whose sum is σ = 1863254016. Its totient is φ = 748695552.

The previous prime is 1221235663. The next prime is 1221235721. The reversal of 1221235715 is 5175321221.

It is a cyclic number.

It is not a de Polignac number, because 1221235715 - 2⁸ = 1221235459 is a prime.

It is a super-2 number, since 2×1221235715² = 2982833343183122450, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

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 63 ways as a sum of consecutive naturals, for example, 3188414 + ... + 3188796.

It is an arithmetic number, because the mean of its divisors is an integer number (29113344).

Almost surely, 2^1221235715 is an apocalyptic number.

1221235715 is a deficient number, since it is larger than the sum of its proper divisors (642018301).

1221235715 is a wasteful number, since it uses less digits than its factorization.

1221235715 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 668.

The product of its digits is 4200, while the sum is 29.

The square root of 1221235715 is about 34946.1831249137. The cubic root of 1221235715 is about 1068.8903729533.

Adding to 1221235715 its reverse (5175321221), we get a palindrome (6396556936).

The spelling of 1221235715 in words is "one billion, two hundred twenty-one million, two hundred thirty-five thousand, seven hundred fifteen".