215221401 has 16 divisors (see below), whose sum is σ = 320224320. Its totient is φ = 142860960.

The previous prime is 215221399. The next prime is 215221403. The reversal of 215221401 is 104122512.

215221401 is a `hidden beast` number, since 2 + 1 + 522 + 140 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (215221399) and next prime (215221403).

It is not a de Polignac number, because 215221401 - 2¹ = 215221399 is a prime.

It is not an unprimeable number, because it can be changed into a prime (215221403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10815 + ... + 23396.

It is an arithmetic number, because the mean of its divisors is an integer number (20014020).

Almost surely, 2^215221401 is an apocalyptic number.

It is an amenable number.

215221401 is a deficient number, since it is larger than the sum of its proper divisors (105002919).

215221401 is a wasteful number, since it uses less digits than its factorization.

215221401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34453 (or 34447 counting only the distinct ones).

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

The square root of 215221401 is about 14670.4260674324. The cubic root of 215221401 is about 599.2782070397.

Adding to 215221401 its reverse (104122512), we get a palindrome (319343913).

It can be divided in two parts, 2 and 15221401, that added together give a triangular number (15221403 = T₅₅₁₇).

The spelling of 215221401 in words is "two hundred fifteen million, two hundred twenty-one thousand, four hundred one".