7447277821 has 2 divisors, whose sum is σ = 7447277822. Its totient is φ = 7447277820.

The previous prime is 7447277779. The next prime is 7447277857. The reversal of 7447277821 is 1287727447.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5357508025 + 2089769796 = 73195^2 + 45714^2 .

It is a cyclic number.

It is not a de Polignac number, because 7447277821 - 2⁷ = 7447277693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7447257821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3723638910 + 3723638911.

It is an arithmetic number, because the mean of its divisors is an integer number (3723638911).

Almost surely, 2^7447277821 is an apocalyptic number.

It is an amenable number.

7447277821 is a deficient number, since it is larger than the sum of its proper divisors (1).

7447277821 is an equidigital number, since it uses as much as digits as its factorization.

7447277821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1229312, while the sum is 49.

The square root of 7447277821 is about 86297.6119078622. The cubic root of 7447277821 is about 1952.8363563808.

The spelling of 7447277821 in words is "seven billion, four hundred forty-seven million, two hundred seventy-seven thousand, eight hundred twenty-one".