47919981 has 4 divisors (see below), whose sum is σ = 63893312. Its totient is φ = 31946652.

The previous prime is 47919979. The next prime is 47919983. The reversal of 47919981 is 18991974.

47919981 is nontrivially palindromic in base 2.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (47919979) and next prime (47919983).

It is not a de Polignac number, because 47919981 - 2¹ = 47919979 is a prime.

It is a super-2 number, since 2×47919981² = 4592649158080722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 47919981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (47919983) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7986661 + ... + 7986666.

It is an arithmetic number, because the mean of its divisors is an integer number (15973328).

Almost surely, 2^47919981 is an apocalyptic number.

It is an amenable number.

47919981 is a deficient number, since it is larger than the sum of its proper divisors (15973331).

47919981 is a wasteful number, since it uses less digits than its factorization.

47919981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15973330.

The product of its digits is 163296, while the sum is 48.

The square root of 47919981 is about 6922.4259475996. The cubic root of 47919981 is about 363.2220560013. Note that the first 3 decimals are identical.

The spelling of 47919981 in words is "forty-seven million, nine hundred nineteen thousand, nine hundred eighty-one".