981288581 has 16 divisors (see below), whose sum is σ = 1240385664. Its totient is φ = 755417664.

The previous prime is 981288577. The next prime is 981288589. The reversal of 981288581 is 185882189.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 981288581 - 2² = 981288577 is a prime.

It is a super-2 number, since 2×981288581² = 1925854558401987122, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (981288589) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 142355 + ... + 149088.

It is an arithmetic number, because the mean of its divisors is an integer number (77524104).

Almost surely, 2^981288581 is an apocalyptic number.

981288581 is a gapful number since it is divisible by the number (91) formed by its first and last digit.

It is an amenable number.

981288581 is a deficient number, since it is larger than the sum of its proper divisors (259097083).

981288581 is a wasteful number, since it uses less digits than its factorization.

981288581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 291500.

The product of its digits is 368640, while the sum is 50.

The square root of 981288581 is about 31325.5260291028. The cubic root of 981288581 is about 993.7235489129.

The spelling of 981288581 in words is "nine hundred eighty-one million, two hundred eighty-eight thousand, five hundred eighty-one".