7121215872 has 256 divisors, whose sum is σ = 22285368000. Its totient is φ = 2234695680.

The previous prime is 7121215861. The next prime is 7121215873. The reversal of 7121215872 is 2785121217.

7121215872 is a `hidden beast` number, since 71 + 2 + 1 + 2 + 1 + 587 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7121215873) 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, 4108318 + ... + 4110050.

Almost surely, 2^7121215872 is an apocalyptic number.

7121215872 is a gapful number since it is divisible by the number (72) 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 7121215872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11142684000).

7121215872 is an abundant number, since it is smaller than the sum of its proper divisors (15164152128).

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

7121215872 is a wasteful number, since it uses less digits than its factorization.

7121215872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1826 (or 1808 counting only the distinct ones).

The product of its digits is 15680, while the sum is 36.

The square root of 7121215872 is about 84387.2968639238. The cubic root of 7121215872 is about 1923.9098451740.

The spelling of 7121215872 in words is "seven billion, one hundred twenty-one million, two hundred fifteen thousand, eight hundred seventy-two".