1272421643136 has 768 divisors, whose sum is σ = 4206647377920. Its totient is φ = 333385113600.

The previous prime is 1272421643131. The next prime is 1272421643137. The reversal of 1272421643136 is 6313461242721.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1272421643131) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 4695282681 + ... + 4695282951.

It is an arithmetic number, because the mean of its divisors is an integer number (5477405440).

Almost surely, 2^{1272421643136} is an apocalyptic number.

1272421643136 is a gapful number since it is divisible by the number (16) 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 1272421643136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2103323688960).

1272421643136 is an abundant number, since it is smaller than the sum of its proper divisors (2934225734784).

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

1272421643136 is a wasteful number, since it uses less digits than its factorization.

1272421643136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 451 (or 410 counting only the distinct ones).

The product of its digits is 290304, while the sum is 42.

Adding to 1272421643136 its reverse (6313461242721), we get a palindrome (7585882885857).

The spelling of 1272421643136 in words is "one trillion, two hundred seventy-two billion, four hundred twenty-one million, six hundred forty-three thousand, one hundred thirty-six".