521126989 has 2 divisors, whose sum is σ = 521126990. Its totient is φ = 521126988.

The previous prime is 521126923. The next prime is 521127001. The reversal of 521126989 is 989621125.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 369024100 + 152102889 = 19210^2 + 12333^2 .

It is a cyclic number.

It is not a de Polignac number, because 521126989 - 2²¹ = 519029837 is a prime.

It is a super-2 number, since 2×521126989² = 543146677328412242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (521126909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260563494 + 260563495.

It is an arithmetic number, because the mean of its divisors is an integer number (260563495).

Almost surely, 2^521126989 is an apocalyptic number.

It is an amenable number.

521126989 is a deficient number, since it is larger than the sum of its proper divisors (1).

521126989 is an equidigital number, since it uses as much as digits as its factorization.

521126989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 77760, while the sum is 43.

The square root of 521126989 is about 22828.2059960918. The cubic root of 521126989 is about 804.7256701904.

The spelling of 521126989 in words is "five hundred twenty-one million, one hundred twenty-six thousand, nine hundred eighty-nine".