1256545531 has 4 divisors (see below), whose sum is σ = 1330459992. Its totient is φ = 1182631072.

The previous prime is 1256545529. The next prime is 1256545541. The reversal of 1256545531 is 1355456521.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1256545531 - 2¹ = 1256545529 is a prime.

It is a super-2 number, since 2×1256545531² = 3157813342952143922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1256545541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36957205 + ... + 36957238.

It is an arithmetic number, because the mean of its divisors is an integer number (332614998).

Almost surely, 2^1256545531 is an apocalyptic number.

1256545531 is a deficient number, since it is larger than the sum of its proper divisors (73914461).

1256545531 is an equidigital number, since it uses as much as digits as its factorization.

1256545531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73914460.

The product of its digits is 90000, while the sum is 37.

The square root of 1256545531 is about 35447.7859816378. The cubic root of 1256545531 is about 1079.0943284643.

The spelling of 1256545531 in words is "one billion, two hundred fifty-six million, five hundred forty-five thousand, five hundred thirty-one".