161331507 has 20 divisors (see below), whose sum is σ = 247519536. Its totient is φ = 104645520.

The previous prime is 161331503. The next prime is 161331517. The reversal of 161331507 is 705133161.

It is not a de Polignac number, because 161331507 - 2² = 161331503 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (161331503) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 23919 + ... + 29912.

Almost surely, 2^161331507 is an apocalyptic number.

161331507 is a deficient number, since it is larger than the sum of its proper divisors (86188029).

161331507 is an equidigital number, since it uses as much as digits as its factorization.

161331507 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53880 (or 53871 counting only the distinct ones).

The product of its (nonzero) digits is 1890, while the sum is 27.

The square root of 161331507 is about 12701.6340287382. The cubic root of 161331507 is about 544.3853092682.

Adding to 161331507 its reverse (705133161), we get a palindrome (866464668).

The spelling of 161331507 in words is "one hundred sixty-one million, three hundred thirty-one thousand, five hundred seven".