158991684 has 72 divisors (see below), whose sum is σ = 406383264. Its totient is φ = 48211200.

The previous prime is 158991631. The next prime is 158991689. The reversal of 158991684 is 486199851.

158991684 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (51).

Its product of digits (622080) is a multiple of the sum of its prime divisors (864).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (158991689) 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 23 ways as a sum of consecutive naturals, for example, 195639 + ... + 196449.

It is an arithmetic number, because the mean of its divisors is an integer number (5644212).

Almost surely, 2^158991684 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 158991684, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (203191632).

158991684 is an abundant number, since it is smaller than the sum of its proper divisors (247391580).

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

158991684 is a wasteful number, since it uses less digits than its factorization.

158991684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 897 (or 864 counting only the distinct ones).

The product of its digits is 622080, while the sum is 51.

The square root of 158991684 is about 12609.1904577574. The cubic root of 158991684 is about 541.7407064814.

The spelling of 158991684 in words is "one hundred fifty-eight million, nine hundred ninety-one thousand, six hundred eighty-four".