47991231 has 8 divisors (see below), whose sum is σ = 71098160. Its totient is φ = 31994136.

The previous prime is 47991227. The next prime is 47991239. The reversal of 47991231 is 13219974.

It is not a de Polignac number, because 47991231 - 2² = 47991227 is a prime.

It is a super-2 number, since 2×47991231² = 4606316505790722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (47991239) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 888700 + ... + 888753.

It is an arithmetic number, because the mean of its divisors is an integer number (8887270).

Almost surely, 2^47991231 is an apocalyptic number.

47991231 is a deficient number, since it is larger than the sum of its proper divisors (23106929).

47991231 is a wasteful number, since it uses less digits than its factorization.

47991231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1777462 (or 1777456 counting only the distinct ones).

The product of its digits is 13608, while the sum is 36.

The square root of 47991231 is about 6927.5703533057. The cubic root of 47991231 is about 363.4019862041.

The spelling of 47991231 in words is "forty-seven million, nine hundred ninety-one thousand, two hundred thirty-one".