1256689980 has 288 divisors, whose sum is σ = 4968722304. Its totient is φ = 249495552.

The previous prime is 1256689979. The next prime is 1256689991. The reversal of 1256689980 is 899866521.

It is a happy number.

1256689980 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

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, 276204 + ... + 280716.

It is an arithmetic number, because the mean of its divisors is an integer number (17252508).

Almost surely, 2^1256689980 is an apocalyptic number.

1256689980 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 1256689980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2484361152).

1256689980 is an abundant number, since it is smaller than the sum of its proper divisors (3712032324).

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

1256689980 is a wasteful number, since it uses less digits than its factorization.

1256689980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4565 (or 4560 counting only the distinct ones).

The product of its (nonzero) digits is 1866240, while the sum is 54.

The square root of 1256689980 is about 35449.8234128183. The cubic root of 1256689980 is about 1079.1356767800.

The spelling of 1256689980 in words is "one billion, two hundred fifty-six million, six hundred eighty-nine thousand, nine hundred eighty".