161213506 has 8 divisors (see below), whose sum is σ = 241935804. Its totient is φ = 80568240.

The previous prime is 161213501. The next prime is 161213513. The reversal of 161213506 is 605312161.

161213506 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 151659225 + 9554281 = 12315^2 + 3091^2 .

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

It is not an unprimeable number, because it can be changed into a prime (161213501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13705 + ... + 22588.

Almost surely, 2^161213506 is an apocalyptic number.

161213506 is a deficient number, since it is larger than the sum of its proper divisors (80722298).

161213506 is a wasteful number, since it uses less digits than its factorization.

161213506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38516.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 161213506 is about 12696.9880680420. The cubic root of 161213506 is about 544.2525522305.

Adding to 161213506 its reverse (605312161), we get a palindrome (766525667).

The spelling of 161213506 in words is "one hundred sixty-one million, two hundred thirteen thousand, five hundred six".