161503331 has 4 divisors (see below), whose sum is σ = 176185464. Its totient is φ = 146821200.

The previous prime is 161503319. The next prime is 161503333. The reversal of 161503331 is 133305161.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 133305161 = 11 ⋅12118651.

It is a cyclic number.

It is not a de Polignac number, because 161503331 - 2⁶ = 161503267 is a prime.

It is a super-2 number, since 2×161503331² = 52166651848191122, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 161503297 and 161503306.

It is not an unprimeable number, because it can be changed into a prime (161503333) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7341050 + ... + 7341071.

It is an arithmetic number, because the mean of its divisors is an integer number (44046366).

Almost surely, 2^161503331 is an apocalyptic number.

161503331 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

161503331 is a deficient number, since it is larger than the sum of its proper divisors (14682133).

161503331 is a wasteful number, since it uses less digits than its factorization.

161503331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14682132.

The product of its (nonzero) digits is 810, while the sum is 23.

The square root of 161503331 is about 12708.3960829052. The cubic root of 161503331 is about 544.5785041695.

Adding to 161503331 its reverse (133305161), we get a palindrome (294808492).

The spelling of 161503331 in words is "one hundred sixty-one million, five hundred three thousand, three hundred thirty-one".