47978257 has 2 divisors, whose sum is σ = 47978258. Its totient is φ = 47978256.

The previous prime is 47978251. The next prime is 47978261. The reversal of 47978257 is 75287974.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 47941776 + 36481 = 6924^2 + 191^2 .

It is a cyclic number.

It is not a de Polignac number, because 47978257 - 2⁷ = 47978129 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 47978257.

It is not a weakly prime, because it can be changed into another prime (47978251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 23989128 + 23989129.

It is an arithmetic number, because the mean of its divisors is an integer number (23989129).

Almost surely, 2^47978257 is an apocalyptic number.

It is an amenable number.

47978257 is a deficient number, since it is larger than the sum of its proper divisors (1).

47978257 is an equidigital number, since it uses as much as digits as its factorization.

47978257 is an evil number, because the sum of its binary digits is even.

The product of its digits is 987840, while the sum is 49.

The square root of 47978257 is about 6926.6338866725. The cubic root of 47978257 is about 363.3692357605.

The spelling of 47978257 in words is "forty-seven million, nine hundred seventy-eight thousand, two hundred fifty-seven".