161215105 has 16 divisors (see below), whose sum is σ = 199386000. Its totient is φ = 125044992.

The previous prime is 161215099. The next prime is 161215111. The reversal of 161215105 is 501512161.

It is a happy number.

161215105 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 (161215099) and next prime (161215111).

It can be written as a sum of positive squares in 8 ways, for example, as 17239104 + 143976001 = 4152^2 + 11999^2 .

It is a cyclic number.

It is not a de Polignac number, because 161215105 - 2²¹ = 159117953 is a prime.

It is a super-2 number, since 2×161215105² = 51980620160322050, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 57271 + ... + 60019.

It is an arithmetic number, because the mean of its divisors is an integer number (12461625).

Almost surely, 2^161215105 is an apocalyptic number.

It is an amenable number.

161215105 is a deficient number, since it is larger than the sum of its proper divisors (38170895).

161215105 is a wasteful number, since it uses less digits than its factorization.

161215105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3108.

The product of its (nonzero) digits is 300, while the sum is 22.

The square root of 161215105 is about 12697.0510355752. The cubic root of 161215105 is about 544.2543516185.

Adding to 161215105 its reverse (501512161), we get a palindrome (662727266).

It can be divided in two parts, 16 and 1215105, that added together give a palindrome (1215121).

The spelling of 161215105 in words is "one hundred sixty-one million, two hundred fifteen thousand, one hundred five".