1256220240 has 80 divisors (see below), whose sum is σ = 4248317376. Its totient is φ = 304537600.

The previous prime is 1256220227. The next prime is 1256220269. The reversal of 1256220240 is 420226521.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 1256220240.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 235281 + ... + 240560.

Almost surely, 2^1256220240 is an apocalyptic number.

1256220240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1256220240 is an abundant number, since it is smaller than the sum of its proper divisors (2992097136).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1256220240 is a wasteful number, since it uses less digits than its factorization.

1256220240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 475868 (or 475862 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 24.

The square root of 1256220240 is about 35443.1973726976. The cubic root of 1256220240 is about 1079.0012027851.

Adding to 1256220240 its reverse (420226521), we get a palindrome (1676446761).

The spelling of 1256220240 in words is "one billion, two hundred fifty-six million, two hundred twenty thousand, two hundred forty".