1264137840 has 600 divisors, whose sum is σ = 5363629920. Its totient is φ = 269982720.

The previous prime is 1264137839. The next prime is 1264137881. The reversal of 1264137840 is 487314621.

1264137840 is a `hidden beast` number, since 1 + 2 + 641 + 3 + 7 + 8 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 1264137795 and 1264137804.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 40778625 + ... + 40778655.

Almost surely, 2^1264137840 is an apocalyptic number.

1264137840 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 1264137840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2681814960).

1264137840 is an abundant number, since it is smaller than the sum of its proper divisors (4099492080).

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

1264137840 is a wasteful number, since it uses less digits than its factorization.

1264137840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123 (or 77 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The square root of 1264137840 is about 35554.7161428691. The cubic root of 1264137840 is about 1081.2633364433.

The spelling of 1264137840 in words is "one billion, two hundred sixty-four million, one hundred thirty-seven thousand, eight hundred forty".