517694981 has 2 divisors, whose sum is σ = 517694982. Its totient is φ = 517694980.

The previous prime is 517694963. The next prime is 517695001. The reversal of 517694981 is 189496715.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 414773956 + 102921025 = 20366^2 + 10145^2 .

It is a cyclic number.

It is not a de Polignac number, because 517694981 - 2¹⁸ = 517432837 is a prime.

It is a super-2 number, since 2×517694981² = 536016186705180722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (517694941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 258847490 + 258847491.

It is an arithmetic number, because the mean of its divisors is an integer number (258847491).

Almost surely, 2^517694981 is an apocalyptic number.

It is an amenable number.

517694981 is a deficient number, since it is larger than the sum of its proper divisors (1).

517694981 is an equidigital number, since it uses as much as digits as its factorization.

517694981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 544320, while the sum is 50.

The square root of 517694981 is about 22752.9114840277. The cubic root of 517694981 is about 802.9552059429.

The spelling of 517694981 in words is "five hundred seventeen million, six hundred ninety-four thousand, nine hundred eighty-one".