2121528637872 has 320 divisors, whose sum is σ = 7122182722560. Its totient is φ = 592084187136.

The previous prime is 2121528637853. The next prime is 2121528637873. The reversal of 2121528637872 is 2787368251212.

2121528637872 is a `hidden beast` number, since 2 + 1 + 2 + 1 + 528 + 6 + 37 + 87 + 2 = 666.

It is a super-2 number, since 2×2121528637872² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (2121528637873) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 36352588 + ... + 36410900.

It is an arithmetic number, because the mean of its divisors is an integer number (22256821008).

Almost surely, 2^{2121528637872} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2121528637872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3561091361280).

2121528637872 is an abundant number, since it is smaller than the sum of its proper divisors (5000654084688).

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

2121528637872 is a wasteful number, since it uses less digits than its factorization.

2121528637872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58617 (or 58605 counting only the distinct ones).

The product of its digits is 4515840, while the sum is 54.

The spelling of 2121528637872 in words is "two trillion, one hundred twenty-one billion, five hundred twenty-eight million, six hundred thirty-seven thousand, eight hundred seventy-two".