47972021 has 4 divisors (see below), whose sum is σ = 47994732. Its totient is φ = 47949312.

The previous prime is 47971999. The next prime is 47972033. The reversal of 47972021 is 12027974.

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 13032100 + 34939921 = 3610^2 + 5911^2 .

It is a cyclic number.

It is not a de Polignac number, because 47972021 - 2¹⁸ = 47709877 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 (47972051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7820 + ... + 12533.

It is an arithmetic number, because the mean of its divisors is an integer number (11998683).

Almost surely, 2^47972021 is an apocalyptic number.

It is an amenable number.

47972021 is a deficient number, since it is larger than the sum of its proper divisors (22711).

47972021 is a wasteful number, since it uses less digits than its factorization.

47972021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22710.

The product of its (nonzero) digits is 7056, while the sum is 32.

The square root of 47972021 is about 6926.1837255447. The cubic root of 47972021 is about 363.3534920405.

Adding to 47972021 its reverse (12027974), we get a palindrome (59999995).

The spelling of 47972021 in words is "forty-seven million, nine hundred seventy-two thousand, twenty-one".