1256278100 has 288 divisors, whose sum is σ = 3706429440. Its totient is φ = 357696000.

The previous prime is 1256278033. The next prime is 1256278117. The reversal of 1256278100 is 18726521.

It is a super-2 number, since 2×1256278100² = 3156469329079220000, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 4535162 + ... + 4535438.

Almost surely, 2^1256278100 is an apocalyptic number.

1256278100 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 1256278100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1853214720).

1256278100 is an abundant number, since it is smaller than the sum of its proper divisors (2450151340).

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

1256278100 is a wasteful number, since it uses less digits than its factorization.

1256278100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 359 (or 352 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 32.

The square root of 1256278100 is about 35444.0135989140. The cubic root of 1256278100 is about 1079.0177683653.

The spelling of 1256278100 in words is "one billion, two hundred fifty-six million, two hundred seventy-eight thousand, one hundred".