1256829640 has 32 divisors (see below), whose sum is σ = 3084946560. Its totient is φ = 457028800.

The previous prime is 1256829611. The next prime is 1256829667. The reversal of 1256829640 is 469286521.

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, 1427776 + ... + 1428655.

It is an arithmetic number, because the mean of its divisors is an integer number (96404580).

Almost surely, 2^1256829640 is an apocalyptic number.

1256829640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1256829640 is an abundant number, since it is smaller than the sum of its proper divisors (1828116920).

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

1256829640 is a wasteful number, since it uses less digits than its factorization.

1256829640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2856453 (or 2856449 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 43.

The square root of 1256829640 is about 35451.7931845485. The cubic root of 1256829640 is about 1079.1756512390.

The spelling of 1256829640 in words is "one billion, two hundred fifty-six million, eight hundred twenty-nine thousand, six hundred forty".