161020521 has 16 divisors (see below), whose sum is σ = 238969920. Its totient is φ = 107157600.

The previous prime is 161020507. The next prime is 161020529. The reversal of 161020521 is 125020161.

161020521 is a `hidden beast` number, since 1 + 610 + 2 + 0 + 52 + 1 = 666.

It is not a de Polignac number, because 161020521 - 2⁷ = 161020393 is a prime.

It is a super-2 number, since 2×161020521² = 51855216366222882, which contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 161020494 and 161020503.

It is not an unprimeable number, because it can be changed into a prime (161020529) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11266 + ... + 21188.

It is an arithmetic number, because the mean of its divisors is an integer number (14935620).

Almost surely, 2^161020521 is an apocalyptic number.

It is an amenable number.

161020521 is a deficient number, since it is larger than the sum of its proper divisors (77949399).

161020521 is an equidigital number, since it uses as much as digits as its factorization.

161020521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10533 (or 10527 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

The square root of 161020521 is about 12689.3861553662. The cubic root of 161020521 is about 544.0352947562.

Adding to 161020521 its reverse (125020161), we get a palindrome (286040682).

The spelling of 161020521 in words is "one hundred sixty-one million, twenty thousand, five hundred twenty-one".