47172421 has 12 divisors (see below), whose sum is σ = 51438720. Its totient is φ = 43095240.

The previous prime is 47172347. The next prime is 47172439. The reversal of 47172421 is 12427174.

It is not a de Polignac number, because 47172421 - 2²¹ = 45075269 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 47172421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (47172451) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 166546 + ... + 166828.

It is an arithmetic number, because the mean of its divisors is an integer number (4286560).

Almost surely, 2^47172421 is an apocalyptic number.

It is an amenable number.

47172421 is a deficient number, since it is larger than the sum of its proper divisors (4266299).

47172421 is an equidigital number, since it uses as much as digits as its factorization.

47172421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 616 (or 333 counting only the distinct ones).

The product of its digits is 3136, while the sum is 28.

The square root of 47172421 is about 6868.2181823236. The cubic root of 47172421 is about 361.3233725878.

Adding to 47172421 its reverse (12427174), we get a palindrome (59599595).

The spelling of 47172421 in words is "forty-seven million, one hundred seventy-two thousand, four hundred twenty-one".