1156664221 has 4 divisors (see below), whose sum is σ = 1168116444. Its totient is φ = 1145212000.

The previous prime is 1156664189. The next prime is 1156664233. The reversal of 1156664221 is 1224666511.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 923491321 + 233172900 = 30389^2 + 15270^2 .

It is a cyclic number.

It is not a de Polignac number, because 1156664221 - 2⁵ = 1156664189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1156664521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5725960 + ... + 5726161.

It is an arithmetic number, because the mean of its divisors is an integer number (292029111).

Almost surely, 2^1156664221 is an apocalyptic number.

It is an amenable number.

1156664221 is a deficient number, since it is larger than the sum of its proper divisors (11452223).

1156664221 is a wasteful number, since it uses less digits than its factorization.

1156664221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11452222.

The product of its digits is 17280, while the sum is 34.

The square root of 1156664221 is about 34009.7665531535. The cubic root of 1156664221 is about 1049.7094346412.

The spelling of 1156664221 in words is "one billion, one hundred fifty-six million, six hundred sixty-four thousand, two hundred twenty-one".