1256635423 has 4 divisors (see below), whose sum is σ = 1257110680. Its totient is φ = 1256160168.

The previous prime is 1256635417. The next prime is 1256635469. The reversal of 1256635423 is 3245366521.

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 1256635423 - 2¹³ = 1256627231 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 (1256630423) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 233640 + ... + 238957.

It is an arithmetic number, because the mean of its divisors is an integer number (314277670).

Almost surely, 2^1256635423 is an apocalyptic number.

1256635423 is a deficient number, since it is larger than the sum of its proper divisors (475257).

1256635423 is an equidigital number, since it uses as much as digits as its factorization.

1256635423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 475256.

The product of its digits is 129600, while the sum is 37.

The square root of 1256635423 is about 35449.0539083908. The cubic root of 1256635423 is about 1079.1200602907.

The spelling of 1256635423 in words is "one billion, two hundred fifty-six million, six hundred thirty-five thousand, four hundred twenty-three".