1221152091 has 8 divisors (see below), whose sum is σ = 1628374080. Its totient is φ = 814015752.

The previous prime is 1221152083. The next prime is 1221152099. The reversal of 1221152091 is 1902511221.

It is an interprime number because it is at equal distance from previous prime (1221152083) and next prime (1221152099).

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

It is not a de Polignac number, because 1221152091 - 2³ = 1221152083 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1221152099) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28440 + ... + 57018.

It is an arithmetic number, because the mean of its divisors is an integer number (203546760).

Almost surely, 2^1221152091 is an apocalyptic number.

1221152091 is a deficient number, since it is larger than the sum of its proper divisors (407221989).

1221152091 is a wasteful number, since it uses less digits than its factorization.

1221152091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42825.

The product of its (nonzero) digits is 360, while the sum is 24.

The square root of 1221152091 is about 34944.9866361400. The cubic root of 1221152091 is about 1068.8659750073.

The spelling of 1221152091 in words is "one billion, two hundred twenty-one million, one hundred fifty-two thousand, ninety-one".