47809991 has 2 divisors, whose sum is σ = 47809992. Its totient is φ = 47809990.

The previous prime is 47809987. The next prime is 47810003. The reversal of 47809991 is 19990874.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 47809991 - 2² = 47809987 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (47809901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 23904995 + 23904996.

It is an arithmetic number, because the mean of its divisors is an integer number (23904996).

Almost surely, 2^47809991 is an apocalyptic number.

47809991 is a deficient number, since it is larger than the sum of its proper divisors (1).

47809991 is an equidigital number, since it uses as much as digits as its factorization.

47809991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 163296, while the sum is 47.

The square root of 47809991 is about 6914.4769144166. The cubic root of 47809991 is about 362.9439437658.

The spelling of 47809991 in words is "forty-seven million, eight hundred nine thousand, nine hundred ninety-one".