47423517721 has 2 divisors, whose sum is σ = 47423517722. Its totient is φ = 47423517720.

The previous prime is 47423517719. The next prime is 47423517767. The reversal of 47423517721 is 12771532474.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 39567177225 + 7856340496 = 198915^2 + 88636^2 .

It is a cyclic number.

It is not a de Polignac number, because 47423517721 - 2¹ = 47423517719 is a prime.

Together with 47423517719, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (47423517121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 23711758860 + 23711758861.

It is an arithmetic number, because the mean of its divisors is an integer number (23711758861).

Almost surely, 2^47423517721 is an apocalyptic number.

It is an amenable number.

47423517721 is a deficient number, since it is larger than the sum of its proper divisors (1).

47423517721 is an equidigital number, since it uses as much as digits as its factorization.

47423517721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 329280, while the sum is 43.

The spelling of 47423517721 in words is "forty-seven billion, four hundred twenty-three million, five hundred seventeen thousand, seven hundred twenty-one".