1659055981 has 8 divisors (see below), whose sum is σ = 1810632384. Its totient is φ = 1507605120.

The previous prime is 1659055969. The next prime is 1659056017. The reversal of 1659055981 is 1895509561.

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

It is a cyclic number.

It is not a de Polignac number, because 1659055981 - 2⁵ = 1659055949 is a prime.

It is a super-2 number, since 2×1659055981² = 5504933496183744722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1659055901) 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, 2596 + ... + 57661.

It is an arithmetic number, because the mean of its divisors is an integer number (226329048).

Almost surely, 2^1659055981 is an apocalyptic number.

1659055981 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1659055981 is a deficient number, since it is larger than the sum of its proper divisors (151576403).

1659055981 is a wasteful number, since it uses less digits than its factorization.

1659055981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62771.

The product of its (nonzero) digits is 486000, while the sum is 49.

The square root of 1659055981 is about 40731.5109098595. The cubic root of 1659055981 is about 1183.8236543901.

The spelling of 1659055981 in words is "one billion, six hundred fifty-nine million, fifty-five thousand, nine hundred eighty-one".