516918981 has 4 divisors (see below), whose sum is σ = 689225312. Its totient is φ = 344612652.

The previous prime is 516918973. The next prime is 516918989. The reversal of 516918981 is 189819615.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (516918973) and next prime (516918989).

It is not a de Polignac number, because 516918981 - 2³ = 516918973 is a prime.

It is a super-2 number, since 2×516918981² = 534410465836156722, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 516918981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (516918989) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 86153161 + ... + 86153166.

It is an arithmetic number, because the mean of its divisors is an integer number (172306328).

Almost surely, 2^516918981 is an apocalyptic number.

It is an amenable number.

516918981 is a deficient number, since it is larger than the sum of its proper divisors (172306331).

516918981 is a wasteful number, since it uses less digits than its factorization.

516918981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172306330.

The product of its digits is 155520, while the sum is 48.

The square root of 516918981 is about 22735.8523262270. The cubic root of 516918981 is about 802.5538081757.

The spelling of 516918981 in words is "five hundred sixteen million, nine hundred eighteen thousand, nine hundred eighty-one".