1256620406 has 8 divisors (see below), whose sum is σ = 1897581600. Its totient is φ = 624093208.

The previous prime is 1256620403. The next prime is 1256620411. The reversal of 1256620406 is 6040266521.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1256620403) 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, 2108126 + ... + 2108721.

It is an arithmetic number, because the mean of its divisors is an integer number (237197700).

Almost surely, 2^1256620406 is an apocalyptic number.

1256620406 is a deficient number, since it is larger than the sum of its proper divisors (640961194).

1256620406 is a wasteful number, since it uses less digits than its factorization.

1256620406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4216998.

The product of its (nonzero) digits is 17280, while the sum is 32.

The square root of 1256620406 is about 35448.8420967456. The cubic root of 1256620406 is about 1079.1157617195.

Adding to 1256620406 its reverse (6040266521), we get a palindrome (7296886927).

The spelling of 1256620406 in words is "one billion, two hundred fifty-six million, six hundred twenty thousand, four hundred six".