158721040 has 20 divisors (see below), whose sum is σ = 369026604. Its totient is φ = 63488384.

The previous prime is 158721019. The next prime is 158721047. The reversal of 158721040 is 40127851.

It can be written as a sum of positive squares in 2 ways, for example, as 67174416 + 91546624 = 8196^2 + 9568^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is not an unprimeable number, because it can be changed into a prime (158721047) 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, 991927 + ... + 992086.

Almost surely, 2^158721040 is an apocalyptic number.

158721040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

158721040 is an abundant number, since it is smaller than the sum of its proper divisors (210305564).

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

158721040 is a wasteful number, since it uses less digits than its factorization.

158721040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1984026 (or 1984020 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 28.

The square root of 158721040 is about 12598.4538733926. The cubic root of 158721040 is about 541.4331387291.

Adding to 158721040 its reverse (40127851), we get a palindrome (198848891).

The spelling of 158721040 in words is "one hundred fifty-eight million, seven hundred twenty-one thousand, forty".