47147991 has 16 divisors (see below), whose sum is σ = 70253568. Its totient is φ = 27876800.

The previous prime is 47147983. The next prime is 47148001. The reversal of 47147991 is 19974174.

It is a cyclic number.

It is not a de Polignac number, because 47147991 - 2³ = 47147983 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (47147951) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16071 + ... + 18776.

It is an arithmetic number, because the mean of its divisors is an integer number (4390848).

Almost surely, 2^47147991 is an apocalyptic number.

47147991 is a gapful number since it is divisible by the number (41) formed by its first and last digit.

47147991 is a deficient number, since it is larger than the sum of its proper divisors (23105577).

47147991 is a wasteful number, since it uses less digits than its factorization.

47147991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34902.

The product of its digits is 63504, while the sum is 42.

The square root of 47147991 is about 6866.4394703514. The cubic root of 47147991 is about 361.2609868826.

The spelling of 47147991 in words is "forty-seven million, one hundred forty-seven thousand, nine hundred ninety-one".