215402121 has 48 divisors (see below), whose sum is σ = 362501568. Its totient is φ = 121804800.

The previous prime is 215402113. The next prime is 215402129. The reversal of 215402121 is 121204512.

215402121 is a `hidden beast` number, since 2 + 1 + 540 + 2 + 121 = 666.

215402121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (215402113) and next prime (215402129).

It is not a de Polignac number, because 215402121 - 2³ = 215402113 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 215402094 and 215402103.

It is not an unprimeable number, because it can be changed into a prime (215402129) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 219985 + ... + 220961.

It is an arithmetic number, because the mean of its divisors is an integer number (7552116).

Almost surely, 2^215402121 is an apocalyptic number.

It is an amenable number.

215402121 is a deficient number, since it is larger than the sum of its proper divisors (147099447).

215402121 is a wasteful number, since it uses less digits than its factorization.

215402121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1142 (or 1139 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 215402121 is about 14676.5841053019. The cubic root of 215402121 is about 599.4458967735.

Adding to 215402121 its reverse (121204512), we get a palindrome (336606633).

The spelling of 215402121 in words is "two hundred fifteen million, four hundred two thousand, one hundred twenty-one".