1221489565 has 8 divisors (see below), whose sum is σ = 1471921920. Its totient is φ = 973102032.

The previous prime is 1221489557. The next prime is 1221489571. The reversal of 1221489565 is 5659841221.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1221489565 - 2³ = 1221489557 is a prime.

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 7 ways as a sum of consecutive naturals, for example, 509889 + ... + 512278.

It is an arithmetic number, because the mean of its divisors is an integer number (183990240).

Almost surely, 2^1221489565 is an apocalyptic number.

It is an amenable number.

1221489565 is a deficient number, since it is larger than the sum of its proper divisors (250432355).

1221489565 is a wasteful number, since it uses less digits than its factorization.

1221489565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1022411.

The product of its digits is 172800, while the sum is 43.

The square root of 1221489565 is about 34949.8149494386. The cubic root of 1221489565 is about 1068.9644288240.

The spelling of 1221489565 in words is "one billion, two hundred twenty-one million, four hundred eighty-nine thousand, five hundred sixty-five".