1256085421 has 6 divisors (see below), whose sum is σ = 1325675022. Its totient is φ = 1189975320.

The previous prime is 1256085403. The next prime is 1256085431. The reversal of 1256085421 is 1245806521.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 1006792900 + 249292521 = 31730^2 + 15789^2 .

It is not a de Polignac number, because 1256085421 - 2⁹ = 1256084909 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1256085401) 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 5 ways as a sum of consecutive naturals, for example, 1739370 + ... + 1740091.

It is an arithmetic number, because the mean of its divisors is an integer number (220945837).

Almost surely, 2^1256085421 is an apocalyptic number.

It is an amenable number.

1256085421 is a deficient number, since it is larger than the sum of its proper divisors (69589601).

1256085421 is an equidigital number, since it uses as much as digits as its factorization.

1256085421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3479499 (or 3479480 counting only the distinct ones).

The product of its (nonzero) digits is 19200, while the sum is 34.

The square root of 1256085421 is about 35441.2954193269. The cubic root of 1256085421 is about 1078.9626015211.

The spelling of 1256085421 in words is "one billion, two hundred fifty-six million, eighty-five thousand, four hundred twenty-one".