1256238816 has 48 divisors (see below), whose sum is σ = 3768718464. Its totient is φ = 358925184.

The previous prime is 1256238799. The next prime is 1256238821. The reversal of 1256238816 is 6188326521.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 934030 + ... + 935373.

It is an arithmetic number, because the mean of its divisors is an integer number (78514968).

Almost surely, 2^1256238816 is an apocalyptic number.

1256238816 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1256238816 is an abundant number, since it is smaller than the sum of its proper divisors (2512479648).

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

1256238816 is a wasteful number, since it uses less digits than its factorization.

1256238816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1869423 (or 1869415 counting only the distinct ones).

The product of its digits is 138240, while the sum is 42.

The square root of 1256238816 is about 35443.4594248361. The cubic root of 1256238816 is about 1079.0065212335.

The spelling of 1256238816 in words is "one billion, two hundred fifty-six million, two hundred thirty-eight thousand, eight hundred sixteen".