1271921560 has 256 divisors, whose sum is σ = 3788467200. Its totient is φ = 373082112.

The previous prime is 1271921543. The next prime is 1271921641. The reversal of 1271921560 is 651291721.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3665307 + ... + 3665653.

It is an arithmetic number, because the mean of its divisors is an integer number (14798700).

Almost surely, 2^1271921560 is an apocalyptic number.

1271921560 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 1271921560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1894233600).

1271921560 is an abundant number, since it is smaller than the sum of its proper divisors (2516545640).

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

1271921560 is a wasteful number, since it uses less digits than its factorization.

1271921560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 450 (or 446 counting only the distinct ones).

The product of its (nonzero) digits is 7560, while the sum is 34.

The square root of 1271921560 is about 35664.0093091060. The cubic root of 1271921560 is about 1083.4780305869.

The spelling of 1271921560 in words is "one billion, two hundred seventy-one million, nine hundred twenty-one thousand, five hundred sixty".