161221047133 has 4 divisors (see below), whose sum is σ = 161225488800. Its totient is φ = 161216605468.

The previous prime is 161221047131. The next prime is 161221047217. The reversal of 161221047133 is 331740122161.

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 161221047133 - 2¹ = 161221047131 is a prime.

It is a super-2 number, since 2×161221047133² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 161221047095 and 161221047104.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161221047131) 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, 2165935 + ... + 2239132.

It is an arithmetic number, because the mean of its divisors is an integer number (40306372200).

Almost surely, 2^161221047133 is an apocalyptic number.

It is an amenable number.

161221047133 is a deficient number, since it is larger than the sum of its proper divisors (4441667).

161221047133 is an equidigital number, since it uses as much as digits as its factorization.

161221047133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4441666.

The product of its (nonzero) digits is 6048, while the sum is 31.

Adding to 161221047133 its reverse (331740122161), we get a palindrome (492961169294).

The spelling of 161221047133 in words is "one hundred sixty-one billion, two hundred twenty-one million, forty-seven thousand, one hundred thirty-three".