1165570221 has 4 divisors (see below), whose sum is σ = 1554093632. Its totient is φ = 777046812.

The previous prime is 1165570213. The next prime is 1165570229. The reversal of 1165570221 is 1220755611.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (1165570213) and next prime (1165570229).

It is not a de Polignac number, because 1165570221 - 2³ = 1165570213 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 (1165570229) 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, 194261701 + ... + 194261706.

It is an arithmetic number, because the mean of its divisors is an integer number (388523408).

Almost surely, 2^1165570221 is an apocalyptic number.

It is an amenable number.

1165570221 is a deficient number, since it is larger than the sum of its proper divisors (388523411).

1165570221 is an equidigital number, since it uses as much as digits as its factorization.

1165570221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 388523410.

The product of its (nonzero) digits is 4200, while the sum is 30.

The square root of 1165570221 is about 34140.4484592690. The cubic root of 1165570221 is about 1052.3967083803.

The spelling of 1165570221 in words is "one billion, one hundred sixty-five million, five hundred seventy thousand, two hundred twenty-one".