6915121920 has 432 divisors, whose sum is σ = 28295991360. Its totient is φ = 1525579776.

The previous prime is 6915121867. The next prime is 6915121921. The reversal of 6915121920 is 291215196.

It is a super-2 number, since 2×6915121920² = 95637822336928972800, which contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (6915121921) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2337082 + ... + 2340038.

It is an arithmetic number, because the mean of its divisors is an integer number (65499980).

Almost surely, 2^6915121920 is an apocalyptic number.

6915121920 is a gapful number since it is divisible by the number (60) 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 6915121920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14147995680).

6915121920 is an abundant number, since it is smaller than the sum of its proper divisors (21380869440).

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

6915121920 is a wasteful number, since it uses less digits than its factorization.

6915121920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3020 (or 3003 counting only the distinct ones).

The product of its (nonzero) digits is 9720, while the sum is 36.

The square root of 6915121920 is about 83157.2120744797. The cubic root of 6915121920 is about 1905.1680096515.

The spelling of 6915121920 in words is "six billion, nine hundred fifteen million, one hundred twenty-one thousand, nine hundred twenty".