47987921 has 2 divisors, whose sum is σ = 47987922. Its totient is φ = 47987920.

The previous prime is 47987909. The next prime is 47987993. The reversal of 47987921 is 12978974.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25897921 + 22090000 = 5089^2 + 4700^2 .

It is a cyclic number.

It is not a de Polignac number, because 47987921 - 2⁶ = 47987857 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (47987021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 23993960 + 23993961.

It is an arithmetic number, because the mean of its divisors is an integer number (23993961).

Almost surely, 2^47987921 is an apocalyptic number.

It is an amenable number.

47987921 is a deficient number, since it is larger than the sum of its proper divisors (1).

47987921 is an equidigital number, since it uses as much as digits as its factorization.

47987921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 254016, while the sum is 47.

The square root of 47987921 is about 6927.3314486893. The cubic root of 47987921 is about 363.3936312872.

The spelling of 47987921 in words is "forty-seven million, nine hundred eighty-seven thousand, nine hundred twenty-one".