47747921 has 4 divisors (see below), whose sum is σ = 51420852. Its totient is φ = 44074992.

The previous prime is 47747873. The next prime is 47747923. The reversal of 47747921 is 12974774.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 19018321 + 28729600 = 4361^2 + 5360^2 .

It is not a de Polignac number, because 47747921 - 2⁶ = 47747857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (47747923) 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, 1836446 + ... + 1836471.

It is an arithmetic number, because the mean of its divisors is an integer number (12855213).

Almost surely, 2^47747921 is an apocalyptic number.

It is an amenable number.

47747921 is a deficient number, since it is larger than the sum of its proper divisors (3672931).

47747921 is a wasteful number, since it uses less digits than its factorization.

47747921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3672930.

The product of its digits is 98784, while the sum is 41.

The square root of 47747921 is about 6909.9870477447. The cubic root of 47747921 is about 362.7868100354.

The spelling of 47747921 in words is "forty-seven million, seven hundred forty-seven thousand, nine hundred twenty-one".