1221280516 has 6 divisors (see below), whose sum is σ = 2137240910. Its totient is φ = 610640256.

The previous prime is 1221280481. The next prime is 1221280523. The reversal of 1221280516 is 6150821221.

It can be written as a sum of positive squares in only one way, i.e., 1221222916 + 57600 = 34946^2 + 240^2 .

It is a super-2 number, since 2×1221280516² = 2983052197522452512, which contains 22 as substring.

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 as a sum of consecutive naturals, namely, 152660061 + ... + 152660068.

Almost surely, 2^1221280516 is an apocalyptic number.

It is an amenable number.

1221280516 is a deficient number, since it is larger than the sum of its proper divisors (915960394).

1221280516 is a wasteful number, since it uses less digits than its factorization.

1221280516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 305320133 (or 305320131 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 28.

The square root of 1221280516 is about 34946.8241189382. The cubic root of 1221280516 is about 1068.9034435318.

The spelling of 1221280516 in words is "one billion, two hundred twenty-one million, two hundred eighty thousand, five hundred sixteen".