7121621872 has 80 divisors (see below), whose sum is σ = 14746199040. Its totient is φ = 3326109696.

The previous prime is 7121621867. The next prime is 7121621873. The reversal of 7121621872 is 2781261217.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7121621873) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1793233 + ... + 1797199.

It is an arithmetic number, because the mean of its divisors is an integer number (184327488).

Almost surely, 2^7121621872 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 7121621872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7373099520).

7121621872 is an abundant number, since it is smaller than the sum of its proper divisors (7624577168).

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

7121621872 is a wasteful number, since it uses less digits than its factorization.

7121621872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4130 (or 4124 counting only the distinct ones).

The product of its digits is 18816, while the sum is 37.

The square root of 7121621872 is about 84389.7024049736. The cubic root of 7121621872 is about 1923.9464069338.

The spelling of 7121621872 in words is "seven billion, one hundred twenty-one million, six hundred twenty-one thousand, eight hundred seventy-two".