1238786640 has 720 divisors, whose sum is σ = 5425933968. Its totient is φ = 250822656.

The previous prime is 1238786623. The next prime is 1238786641. The reversal of 1238786640 is 466878321.

It can be written as a sum of positive squares in 8 ways, for example, as 28224 + 1238758416 = 168^2 + 35196^2 .

It is a tau number, because it is divible by the number of its divisors (720).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1238786641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 16969644 + ... + 16969716.

Almost surely, 2^1238786640 is an apocalyptic number.

1238786640 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 1238786640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2712966984).

1238786640 is an abundant number, since it is smaller than the sum of its proper divisors (4187147328).

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

1238786640 is a wasteful number, since it uses less digits than its factorization.

1238786640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156 (or 140 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 45.

The square root of 1238786640 is about 35196.4009523701. The cubic root of 1238786640 is about 1073.9865379127.

The spelling of 1238786640 in words is "one billion, two hundred thirty-eight million, seven hundred eighty-six thousand, six hundred forty".