158640981 has 8 divisors (see below), whose sum is σ = 218344704. Its totient is φ = 102348960.

The previous prime is 158640973. The next prime is 158640997. The reversal of 158640981 is 189046851.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 158640981 - 2³ = 158640973 is a prime.

It is a super-2 number, since 2×158640981² = 50333921705284722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (158640281) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 852816 + ... + 853001.

It is an arithmetic number, because the mean of its divisors is an integer number (27293088).

Almost surely, 2^158640981 is an apocalyptic number.

It is an amenable number.

158640981 is a deficient number, since it is larger than the sum of its proper divisors (59703723).

158640981 is a wasteful number, since it uses less digits than its factorization.

158640981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1705851.

The product of its (nonzero) digits is 69120, while the sum is 42.

The square root of 158640981 is about 12595.2761382988. The cubic root of 158640981 is about 541.3420903385.

The spelling of 158640981 in words is "one hundred fifty-eight million, six hundred forty thousand, nine hundred eighty-one".