7147777921 has 2 divisors, whose sum is σ = 7147777922. Its totient is φ = 7147777920.

The previous prime is 7147777913. The next prime is 7147777933. The reversal of 7147777921 is 1297777417.

7147777921 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5929000000 + 1218777921 = 77000^2 + 34911^2 .

It is a cyclic number.

It is not a de Polignac number, because 7147777921 - 2³ = 7147777913 is a prime.

It is not a weakly prime, because it can be changed into another prime (7147777121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3573888960 + 3573888961.

It is an arithmetic number, because the mean of its divisors is an integer number (3573888961).

Almost surely, 2^7147777921 is an apocalyptic number.

It is an amenable number.

7147777921 is a deficient number, since it is larger than the sum of its proper divisors (1).

7147777921 is an equidigital number, since it uses as much as digits as its factorization.

7147777921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1210104, while the sum is 52.

The square root of 7147777921 is about 84544.5321768357. The cubic root of 7147777921 is about 1926.2989306894.

The spelling of 7147777921 in words is "seven billion, one hundred forty-seven million, seven hundred seventy-seven thousand, nine hundred twenty-one".