215121155 has 8 divisors (see below), whose sum is σ = 259099584. Its totient is φ = 171460800.

The previous prime is 215121133. The next prime is 215121161. The reversal of 215121155 is 551121512.

215121155 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 215121155 - 2⁶ = 215121091 is a prime.

It is a super-2 number, since 2×215121155² = 92554222657068050, which contains 22 as substring.

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 215121155.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 78026 + ... + 80735.

It is an arithmetic number, because the mean of its divisors is an integer number (32387448).

Almost surely, 2^215121155 is an apocalyptic number.

215121155 is a deficient number, since it is larger than the sum of its proper divisors (43978429).

215121155 is a wasteful number, since it uses less digits than its factorization.

215121155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159037.

The product of its digits is 500, while the sum is 23.

The square root of 215121155 is about 14667.0090679729. The cubic root of 215121155 is about 599.1851484923.

Adding to 215121155 its reverse (551121512), we get a palindrome (766242667).

The spelling of 215121155 in words is "two hundred fifteen million, one hundred twenty-one thousand, one hundred fifty-five".