161521788 has 12 divisors (see below), whose sum is σ = 376884200. Its totient is φ = 53840592.

The previous prime is 161521783. The next prime is 161521807. The reversal of 161521788 is 887125161.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161521783) 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, 6730063 + ... + 6730086.

Almost surely, 2^161521788 is an apocalyptic number.

It is an amenable number.

161521788 is an abundant number, since it is smaller than the sum of its proper divisors (215362412).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161521788 is a wasteful number, since it uses less digits than its factorization.

161521788 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13460156 (or 13460154 counting only the distinct ones).

The product of its digits is 26880, while the sum is 39.

The square root of 161521788 is about 12709.1222356227. The cubic root of 161521788 is about 544.5992486386.

The spelling of 161521788 in words is "one hundred sixty-one million, five hundred twenty-one thousand, seven hundred eighty-eight".