1221384558 has 16 divisors (see below), whose sum is σ = 2470217040. Its totient is φ = 402553536.

The previous prime is 1221384557. The next prime is 1221384611. The reversal of 1221384558 is 8554831221.

1221384558 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221384551) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1143085 + ... + 1144152.

It is an arithmetic number, because the mean of its divisors is an integer number (154388565).

Almost surely, 2^1221384558 is an apocalyptic number.

1221384558 is an abundant number, since it is smaller than the sum of its proper divisors (1248832482).

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

1221384558 is a wasteful number, since it uses less digits than its factorization.

1221384558 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2287331.

The product of its digits is 76800, while the sum is 39.

The square root of 1221384558 is about 34948.3126631315. The cubic root of 1221384558 is about 1068.9337962893.

The spelling of 1221384558 in words is "one billion, two hundred twenty-one million, three hundred eighty-four thousand, five hundred fifty-eight".