1221535442 has 16 divisors (see below), whose sum is σ = 1941511680. Its totient is φ = 574417728.

The previous prime is 1221535417. The next prime is 1221535457. The reversal of 1221535442 is 2445351221.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36443 + ... + 61409.

It is an arithmetic number, because the mean of its divisors is an integer number (121344480).

Almost surely, 2^1221535442 is an apocalyptic number.

1221535442 is a deficient number, since it is larger than the sum of its proper divisors (719976238).

1221535442 is a wasteful number, since it uses less digits than its factorization.

1221535442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26425.

The product of its digits is 9600, while the sum is 29.

The square root of 1221535442 is about 34950.4712700702. The cubic root of 1221535442 is about 1068.9778114645.

Adding to 1221535442 its reverse (2445351221), we get a palindrome (3666886663).

The spelling of 1221535442 in words is "one billion, two hundred twenty-one million, five hundred thirty-five thousand, four hundred forty-two".