1221369056 has 24 divisors (see below), whose sum is σ = 2427922224. Its totient is φ = 604753920.

The previous prime is 1221369053. The next prime is 1221369091. The reversal of 1221369056 is 6509631221.

It is a super-2 number, since 2×1221369056² = 2983484741908662272, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221369053) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 181985 + ... + 188576.

It is an arithmetic number, because the mean of its divisors is an integer number (101163426).

Almost surely, 2^1221369056 is an apocalyptic number.

1221369056 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1221369056 is a deficient number, since it is larger than the sum of its proper divisors (1206553168).

1221369056 is a wasteful number, since it uses less digits than its factorization.

1221369056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 370674 (or 370666 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 35.

The square root of 1221369056 is about 34948.0908777575. The cubic root of 1221369056 is about 1068.9292739130.

The spelling of 1221369056 in words is "one billion, two hundred twenty-one million, three hundred sixty-nine thousand, fifty-six".