1271967840 has 768 divisors, whose sum is σ = 5486745600. Its totient is φ = 270950400.

The previous prime is 1271967817. The next prime is 1271967847. The reversal of 1271967840 is 487691721.

It is a happy number.

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 (1271967847) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 17915005 + ... + 17915075.

It is an arithmetic number, because the mean of its divisors is an integer number (7144200).

Almost surely, 2^1271967840 is an apocalyptic number.

1271967840 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 1271967840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2743372800).

1271967840 is an abundant number, since it is smaller than the sum of its proper divisors (4214777760).

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

1271967840 is a wasteful number, since it uses less digits than its factorization.

1271967840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 148 (or 134 counting only the distinct ones).

The product of its (nonzero) digits is 169344, while the sum is 45.

The square root of 1271967840 is about 35664.6581365923. The cubic root of 1271967840 is about 1083.4911715323.

The spelling of 1271967840 in words is "one billion, two hundred seventy-one million, nine hundred sixty-seven thousand, eight hundred forty".