1247985816 has 128 divisors (see below), whose sum is σ = 4094668800. Its totient is φ = 307082880.

The previous prime is 1247985811. The next prime is 1247985821. The reversal of 1247985816 is 6185897421.

It is an interprime number because it is at equal distance from previous prime (1247985811) and next prime (1247985821).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1247985811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 17341 + ... + 52883.

It is an arithmetic number, because the mean of its divisors is an integer number (31989600).

Almost surely, 2^1247985816 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1247985816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2047334400).

1247985816 is an abundant number, since it is smaller than the sum of its proper divisors (2846682984).

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

1247985816 is a wasteful number, since it uses less digits than its factorization.

1247985816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35589 (or 35585 counting only the distinct ones).

The product of its digits is 967680, while the sum is 51.

The square root of 1247985816 is about 35326.8427120228. The cubic root of 1247985816 is about 1076.6384435832.

The spelling of 1247985816 in words is "one billion, two hundred forty-seven million, nine hundred eighty-five thousand, eight hundred sixteen".