1221530788 has 6 divisors (see below), whose sum is σ = 2137678886. Its totient is φ = 610765392.

The previous prime is 1221530747. The next prime is 1221530833. The reversal of 1221530788 is 8870351221.

It can be written as a sum of positive squares in only one way, i.e., 1218847744 + 2683044 = 34912^2 + 1638^2 .

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 152691345 + ... + 152691352.

Almost surely, 2^1221530788 is an apocalyptic number.

It is an amenable number.

1221530788 is a deficient number, since it is larger than the sum of its proper divisors (916148098).

1221530788 is a wasteful number, since it uses less digits than its factorization.

1221530788 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 305382701 (or 305382699 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 37.

The square root of 1221530788 is about 34950.4046900748. The cubic root of 1221530788 is about 1068.9764538756.

The spelling of 1221530788 in words is "one billion, two hundred twenty-one million, five hundred thirty thousand, seven hundred eighty-eight".