1256532521 has 2 divisors, whose sum is σ = 1256532522. Its totient is φ = 1256532520.

The previous prime is 1256532467. The next prime is 1256532523. The reversal of 1256532521 is 1252356521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1236506896 + 20025625 = 35164^2 + 4475^2 .

It is a cyclic number.

It is not a de Polignac number, because 1256532521 - 2¹⁴ = 1256516137 is a prime.

Together with 1256532523, 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 (1256532523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 628266260 + 628266261.

It is an arithmetic number, because the mean of its divisors is an integer number (628266261).

Almost surely, 2^1256532521 is an apocalyptic number.

It is an amenable number.

1256532521 is a deficient number, since it is larger than the sum of its proper divisors (1).

1256532521 is an equidigital number, since it uses as much as digits as its factorization.

1256532521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18000, while the sum is 32.

The square root of 1256532521 is about 35447.6024718175. The cubic root of 1256532521 is about 1079.0906042152.

The spelling of 1256532521 in words is "one billion, two hundred fifty-six million, five hundred thirty-two thousand, five hundred twenty-one".