47821723981 has 4 divisors (see below), whose sum is σ = 48030552700. Its totient is φ = 47612895264.

The previous prime is 47821723969. The next prime is 47821723991. The reversal of 47821723981 is 18932712874.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18932712874 = 2 ⋅9466356437.

It can be written as a sum of positive squares in 2 ways, for example, as 41928705225 + 5893018756 = 204765^2 + 76766^2 .

It is a cyclic number.

It is not a de Polignac number, because 47821723981 - 2¹¹ = 47821721933 is a prime.

It is a super-2 number, since 2×47821723981² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (47821723931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 104414016 + ... + 104414473.

It is an arithmetic number, because the mean of its divisors is an integer number (12007638175).

Almost surely, 2^47821723981 is an apocalyptic number.

It is an amenable number.

47821723981 is a deficient number, since it is larger than the sum of its proper divisors (208828719).

47821723981 is a wasteful number, since it uses less digits than its factorization.

47821723981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 208828718.

The product of its digits is 1354752, while the sum is 52.

The spelling of 47821723981 in words is "forty-seven billion, eight hundred twenty-one million, seven hundred twenty-three thousand, nine hundred eighty-one".