521056139 has 2 divisors, whose sum is σ = 521056140. Its totient is φ = 521056138.

The previous prime is 521056127. The next prime is 521056141. The reversal of 521056139 is 931650125.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 521056139 - 2²⁰ = 520007563 is a prime.

Together with 521056141, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (521056169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260528069 + 260528070.

It is an arithmetic number, because the mean of its divisors is an integer number (260528070).

Almost surely, 2^521056139 is an apocalyptic number.

521056139 is a deficient number, since it is larger than the sum of its proper divisors (1).

521056139 is an equidigital number, since it uses as much as digits as its factorization.

521056139 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8100, while the sum is 32.

The square root of 521056139 is about 22826.6541350238. The cubic root of 521056139 is about 804.6891996186.

The spelling of 521056139 in words is "five hundred twenty-one million, fifty-six thousand, one hundred thirty-nine".