161531306 has 16 divisors (see below), whose sum is σ = 248845344. Its totient is φ = 78596784.

The previous prime is 161531303. The next prime is 161531317. The reversal of 161531306 is 603135161.

It is not an unprimeable number, because it can be changed into a prime (161531303) 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, 21020 + ... + 27656.

It is an arithmetic number, because the mean of its divisors is an integer number (15552834).

Almost surely, 2^161531306 is an apocalyptic number.

161531306 is a deficient number, since it is larger than the sum of its proper divisors (87314038).

161531306 is a wasteful number, since it uses less digits than its factorization.

161531306 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6965.

The product of its (nonzero) digits is 1620, while the sum is 26.

The square root of 161531306 is about 12709.4966855497. The cubic root of 161531306 is about 544.6099456348.

Adding to 161531306 its reverse (603135161), we get a palindrome (764666467).

The spelling of 161531306 in words is "one hundred sixty-one million, five hundred thirty-one thousand, three hundred six".