47388821 has 4 divisors (see below), whose sum is σ = 47417100. Its totient is φ = 47360544.

The previous prime is 47388811. The next prime is 47388829. The reversal of 47388821 is 12888374.

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 29866225 + 17522596 = 5465^2 + 4186^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-47388821 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (47388829) 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, 11456 + ... + 15033.

It is an arithmetic number, because the mean of its divisors is an integer number (11854275).

Almost surely, 2^47388821 is an apocalyptic number.

It is an amenable number.

47388821 is a deficient number, since it is larger than the sum of its proper divisors (28279).

47388821 is a wasteful number, since it uses less digits than its factorization.

47388821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28278.

The product of its digits is 86016, while the sum is 41.

The square root of 47388821 is about 6883.9538784045. The cubic root of 47388821 is about 361.8750446296.

The spelling of 47388821 in words is "forty-seven million, three hundred eighty-eight thousand, eight hundred twenty-one".