520771981 has 2 divisors, whose sum is σ = 520771982. Its totient is φ = 520771980.

The previous prime is 520771973. The next prime is 520771991. The reversal of 520771981 is 189177025.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 489913956 + 30858025 = 22134^2 + 5555^2 .

It is a cyclic number.

It is not a de Polignac number, because 520771981 - 2³ = 520771973 is a prime.

It is a super-2 number, since 2×520771981² = 542406912389328722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (520771921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260385990 + 260385991.

It is an arithmetic number, because the mean of its divisors is an integer number (260385991).

Almost surely, 2^520771981 is an apocalyptic number.

It is an amenable number.

520771981 is a deficient number, since it is larger than the sum of its proper divisors (1).

520771981 is an equidigital number, since it uses as much as digits as its factorization.

520771981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 35280, while the sum is 40.

The square root of 520771981 is about 22820.4290275183. The cubic root of 520771981 is about 804.5428939166.

The spelling of 520771981 in words is "five hundred twenty million, seven hundred seventy-one thousand, nine hundred eighty-one".