161421755008 has 16 divisors (see below), whose sum is σ = 321582402810. Its totient is φ = 80710877440.

The previous prime is 161421754999. The next prime is 161421755119. The reversal of 161421755008 is 800557124161.

It can be written as a sum of positive squares in only one way, i.e., 149979601984 + 11442153024 = 387272^2 + 106968^2 .

It is a tau number, because it is divible by the number of its divisors (16).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 630553603 + ... + 630553858.

Almost surely, 2^161421755008 is an apocalyptic number.

It is an amenable number.

161421755008 is a deficient number, since it is larger than the sum of its proper divisors (160160647802).

161421755008 is an equidigital number, since it uses as much as digits as its factorization.

161421755008 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1261107475 (or 1261107463 counting only the distinct ones).

The product of its (nonzero) digits is 67200, while the sum is 40.

Adding to 161421755008 its reverse (800557124161), we get a palindrome (961978879169).

The spelling of 161421755008 in words is "one hundred sixty-one billion, four hundred twenty-one million, seven hundred fifty-five thousand, eight".