161521337 has 4 divisors (see below), whose sum is σ = 170022480. Its totient is φ = 153020196.

The previous prime is 161521313. The next prime is 161521357. The reversal of 161521337 is 733125161.

161521337 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 161521337 - 2⁶ = 161521273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161521307) 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, 4250543 + ... + 4250580.

It is an arithmetic number, because the mean of its divisors is an integer number (42505620).

Almost surely, 2^161521337 is an apocalyptic number.

It is an amenable number.

161521337 is a deficient number, since it is larger than the sum of its proper divisors (8501143).

161521337 is an equidigital number, since it uses as much as digits as its factorization.

161521337 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8501142.

The product of its digits is 3780, while the sum is 29.

The square root of 161521337 is about 12709.1044924495. The cubic root of 161521337 is about 544.5987417628.

Adding to 161521337 its reverse (733125161), we get a palindrome (894646498).

The spelling of 161521337 in words is "one hundred sixty-one million, five hundred twenty-one thousand, three hundred thirty-seven".