518720981 has 2 divisors, whose sum is σ = 518720982. Its totient is φ = 518720980.

The previous prime is 518720977. The next prime is 518720989. The reversal of 518720981 is 189027815.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 281098756 + 237622225 = 16766^2 + 15415^2 .

It is a cyclic number.

It is not a de Polignac number, because 518720981 - 2² = 518720977 is a prime.

It is a super-2 number, since 2×518720981² = 538142912259204722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (518720989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 259360490 + 259360491.

It is an arithmetic number, because the mean of its divisors is an integer number (259360491).

Almost surely, 2^518720981 is an apocalyptic number.

It is an amenable number.

518720981 is a deficient number, since it is larger than the sum of its proper divisors (1).

518720981 is an equidigital number, since it uses as much as digits as its factorization.

518720981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40320, while the sum is 41.

The square root of 518720981 is about 22775.4468891392. The cubic root of 518720981 is about 803.4853047008.

The spelling of 518720981 in words is "five hundred eighteen million, seven hundred twenty thousand, nine hundred eighty-one".