215610161 has 8 divisors (see below), whose sum is σ = 232705704. Its totient is φ = 198587520.

The previous prime is 215610151. The next prime is 215610181. The reversal of 215610161 is 161016512.

It can be written as a sum of positive squares in 4 ways, for example, as 34869025 + 180741136 = 5905^2 + 13444^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 215610161 - 2¹⁸ = 215348017 is a prime.

It is a super-4 number, since 4×215610161⁴ (a number of 34 digits) contains 4444 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (215610121) 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, 11996 + ... + 23981.

It is an arithmetic number, because the mean of its divisors is an integer number (29088213).

Almost surely, 2^215610161 is an apocalyptic number.

It is an amenable number.

215610161 is a deficient number, since it is larger than the sum of its proper divisors (17095543).

215610161 is a wasteful number, since it uses less digits than its factorization.

215610161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36451.

The product of its (nonzero) digits is 360, while the sum is 23.

The square root of 215610161 is about 14683.6698750687. The cubic root of 215610161 is about 599.6388205890.

Adding to 215610161 its reverse (161016512), we get a palindrome (376626673).

The spelling of 215610161 in words is "two hundred fifteen million, six hundred ten thousand, one hundred sixty-one".