2158669981 has 8 divisors (see below), whose sum is σ = 2326139424. Its totient is φ = 1991403120.

The previous prime is 2158669969. The next prime is 2158670051. The reversal of 2158669981 is 1899668512.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2158669981 is a prime.

It is a super-2 number, since 2×2158669981² = 9319712173741080722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2158669901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28135 + ... + 71476.

It is an arithmetic number, because the mean of its divisors is an integer number (290767428).

Almost surely, 2^2158669981 is an apocalyptic number.

It is an amenable number.

2158669981 is a deficient number, since it is larger than the sum of its proper divisors (167469443).

2158669981 is a wasteful number, since it uses less digits than its factorization.

2158669981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101291.

The product of its digits is 1866240, while the sum is 55.

The square root of 2158669981 is about 46461.4892249484. The cubic root of 2158669981 is about 1292.3954411113.

The spelling of 2158669981 in words is "two billion, one hundred fifty-eight million, six hundred sixty-nine thousand, nine hundred eighty-one".