7911907121 has 4 divisors (see below), whose sum is σ = 7923663972. Its totient is φ = 7900150272.

The previous prime is 7911907109. The next prime is 7911907147. The reversal of 7911907121 is 1217091197.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4964611600 + 2947295521 = 70460^2 + 54289^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7911907121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7911907921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5877416 + ... + 5878761.

It is an arithmetic number, because the mean of its divisors is an integer number (1980915993).

Almost surely, 2^7911907121 is an apocalyptic number.

It is an amenable number.

7911907121 is a deficient number, since it is larger than the sum of its proper divisors (11756851).

7911907121 is a wasteful number, since it uses less digits than its factorization.

7911907121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11756850.

The product of its (nonzero) digits is 7938, while the sum is 38.

The square root of 7911907121 is about 88948.9017413931. The cubic root of 7911907121 is about 1992.6318150100.

The spelling of 7911907121 in words is "seven billion, nine hundred eleven million, nine hundred seven thousand, one hundred twenty-one".