1221605142 has 32 divisors (see below), whose sum is σ = 2589374304. Its totient is φ = 382886400.

The previous prime is 1221605137. The next prime is 1221605149. The reversal of 1221605142 is 2415061221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221605149) 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 15 ways as a sum of consecutive naturals, for example, 115392 + ... + 125532.

It is an arithmetic number, because the mean of its divisors is an integer number (80917947).

Almost surely, 2^1221605142 is an apocalyptic number.

1221605142 is an abundant number, since it is smaller than the sum of its proper divisors (1367769162).

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

1221605142 is a wasteful number, since it uses less digits than its factorization.

1221605142 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11344.

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 1221605142 is about 34951.4683811711. The cubic root of 1221605142 is about 1068.9981427989.

Adding to 1221605142 its reverse (2415061221), we get a palindrome (3636666363).

The spelling of 1221605142 in words is "one billion, two hundred twenty-one million, six hundred five thousand, one hundred forty-two".