513139981 has 2 divisors, whose sum is σ = 513139982. Its totient is φ = 513139980.

The previous prime is 513139967. The next prime is 513140009. The reversal of 513139981 is 189931315.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 281065225 + 232074756 = 16765^2 + 15234^2 .

It is a cyclic number.

It is not a de Polignac number, because 513139981 - 2¹⁹ = 512615693 is a prime.

It is a super-2 number, since 2×513139981² = 526625280201360722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (513139901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 256569990 + 256569991.

It is an arithmetic number, because the mean of its divisors is an integer number (256569991).

Almost surely, 2^513139981 is an apocalyptic number.

It is an amenable number.

513139981 is a deficient number, since it is larger than the sum of its proper divisors (1).

513139981 is an equidigital number, since it uses as much as digits as its factorization.

513139981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 29160, while the sum is 40.

The square root of 513139981 is about 22652.5932511048. The cubic root of 513139981 is about 800.5932999893.

The spelling of 513139981 in words is "five hundred thirteen million, one hundred thirty-nine thousand, nine hundred eighty-one".