1272291840 has 320 divisors, whose sum is σ = 4596134400. Its totient is φ = 333545472.

The previous prime is 1272291827. The next prime is 1272291841. The reversal of 1272291840 is 481922721.

It is a tau number, because it is divible by the number of its divisors (320).

It is a super-2 number, since 2×1272291840² = 3237453052261171200, which contains 22 as substring.

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 = 1272291795 and 1272291804.

It is not an unprimeable number, because it can be changed into a prime (1272291841) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5460364 + ... + 5460596.

It is an arithmetic number, because the mean of its divisors is an integer number (14362920).

Almost surely, 2^1272291840 is an apocalyptic number.

1272291840 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 1272291840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2298067200).

1272291840 is an abundant number, since it is smaller than the sum of its proper divisors (3323842560).

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

1272291840 is an equidigital number, since it uses as much as digits as its factorization.

1272291840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 344 (or 322 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The square root of 1272291840 is about 35669.2001592410. The cubic root of 1272291840 is about 1083.5831605815.

The spelling of 1272291840 in words is "one billion, two hundred seventy-two million, two hundred ninety-one thousand, eight hundred forty".