215121109 has 8 divisors (see below), whose sum is σ = 247789568. Its totient is φ = 182936880.

The previous prime is 215121107. The next prime is 215121133. The reversal of 215121109 is 901121512.

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

It is not a de Polignac number, because 215121109 - 2¹ = 215121107 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 215121109.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215121103) 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, 120102 + ... + 121879.

It is an arithmetic number, because the mean of its divisors is an integer number (30973696).

Almost surely, 2^215121109 is an apocalyptic number.

It is an amenable number.

215121109 is a deficient number, since it is larger than the sum of its proper divisors (32668459).

215121109 is a wasteful number, since it uses less digits than its factorization.

215121109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 242115.

The product of its (nonzero) digits is 180, while the sum is 22.

The square root of 215121109 is about 14667.0074998276. The cubic root of 215121109 is about 599.1851057838.

The spelling of 215121109 in words is "two hundred fifteen million, one hundred twenty-one thousand, one hundred nine".