1221551022 has 32 divisors (see below), whose sum is σ = 2555336448. Its totient is φ = 388561536.

The previous prime is 1221551017. The next prime is 1221551039. The reversal of 1221551022 is 2201551221.

It is a self number, because there is not a number n which added to its sum of digits gives 1221551022.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 49533 + ... + 69975.

It is an arithmetic number, because the mean of its divisors is an integer number (79854264).

Almost surely, 2^1221551022 is an apocalyptic number.

1221551022 is an abundant number, since it is smaller than the sum of its proper divisors (1333785426).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1221551022 is a wasteful number, since it uses less digits than its factorization.

1221551022 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20904.

The product of its (nonzero) digits is 400, while the sum is 21.

The square root of 1221551022 is about 34950.6941561967. The cubic root of 1221551022 is about 1068.9823561829.

The spelling of 1221551022 in words is "one billion, two hundred twenty-one million, five hundred fifty-one thousand, twenty-two".