1256505600 has 216 divisors, whose sum is σ = 4739627200. Its totient is φ = 287170560.

The previous prime is 1256505589. The next prime is 1256505611. The reversal of 1256505600 is 65056521.

It is an interprime number because it is at equal distance from previous prime (1256505589) and next prime (1256505611).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 129726 + ... + 139074.

Almost surely, 2^1256505600 is an apocalyptic number.

1256505600 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1256505600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2369813600).

1256505600 is an abundant number, since it is smaller than the sum of its proper divisors (3483121600).

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

1256505600 is an equidigital number, since it uses as much as digits as its factorization.

1256505600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9385 (or 9366 counting only the distinct ones).

The product of its (nonzero) digits is 9000, while the sum is 30.

The square root of 1256505600 is about 35447.2227402938. Note that the first 3 decimals coincide. The cubic root of 1256505600 is about 1079.0828977147.

The spelling of 1256505600 in words is "one billion, two hundred fifty-six million, five hundred five thousand, six hundred".