1221716559 has 48 divisors (see below), whose sum is σ = 1948053888. Its totient is φ = 678702528.

The previous prime is 1221716557. The next prime is 1221716569. The reversal of 1221716559 is 9556171221.

1221716559 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 1221716559 - 2¹ = 1221716557 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221716557) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2193109 + ... + 2193665.

It is an arithmetic number, because the mean of its divisors is an integer number (40584456).

Almost surely, 2^1221716559 is an apocalyptic number.

1221716559 is a deficient number, since it is larger than the sum of its proper divisors (726337329).

1221716559 is a wasteful number, since it uses less digits than its factorization.

1221716559 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 964 (or 957 counting only the distinct ones).

The product of its digits is 37800, while the sum is 39.

The square root of 1221716559 is about 34953.0622263629. The cubic root of 1221716559 is about 1069.0306412828.

The spelling of 1221716559 in words is "one billion, two hundred twenty-one million, seven hundred sixteen thousand, five hundred fifty-nine".