1281645632 has 56 divisors (see below), whose sum is σ = 2610209664. Its totient is φ = 624092672.

The previous prime is 1281645619. The next prime is 1281645641. The reversal of 1281645632 is 2365461821.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 681878 + ... + 683754.

Almost surely, 2^1281645632 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 1281645632, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1305104832).

1281645632 is an abundant number, since it is smaller than the sum of its proper divisors (1328564032).

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

1281645632 is a wasteful number, since it uses less digits than its factorization.

1281645632 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2163 (or 2153 counting only the distinct ones).

The product of its digits is 69120, while the sum is 38.

The square root of 1281645632 is about 35800.0786591315. The cubic root of 1281645632 is about 1086.2321528414.

The spelling of 1281645632 in words is "one billion, two hundred eighty-one million, six hundred forty-five thousand, six hundred thirty-two".