1278385632 has 144 divisors (see below), whose sum is σ = 3899180880. Its totient is φ = 407455488.

The previous prime is 1278385613. The next prime is 1278385637. The reversal of 1278385632 is 2365838721.

1278385632 is a `hidden beast` number, since 1 + 2 + 7 + 8 + 3 + 8 + 5 + 632 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1278385637) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 455658 + ... + 458454.

It is an arithmetic number, because the mean of its divisors is an integer number (27077645).

Almost surely, 2^1278385632 is an apocalyptic number.

1278385632 is a gapful number since it is divisible by the number (12) 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 1278385632, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1949590440).

1278385632 is an abundant number, since it is smaller than the sum of its proper divisors (2620795248).

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

1278385632 is a wasteful number, since it uses less digits than its factorization.

1278385632 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2862 (or 2825 counting only the distinct ones).

The product of its digits is 483840, while the sum is 45.

The square root of 1278385632 is about 35754.5190430524. The cubic root of 1278385632 is about 1085.3103890870.

The spelling of 1278385632 in words is "one billion, two hundred seventy-eight million, three hundred eighty-five thousand, six hundred thirty-two".