671542921 has 16 divisors (see below), whose sum is σ = 782431488. Its totient is φ = 564480000.

The previous prime is 671542889. The next prime is 671542939. The reversal of 671542921 is 129245176.

It is not a de Polignac number, because 671542921 - 2⁵ = 671542889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (671542951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 92421 + ... + 99421.

It is an arithmetic number, because the mean of its divisors is an integer number (48901968).

Almost surely, 2^671542921 is an apocalyptic number.

It is an amenable number.

671542921 is a deficient number, since it is larger than the sum of its proper divisors (110888567).

671542921 is a wasteful number, since it uses less digits than its factorization.

671542921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7272.

The product of its digits is 30240, while the sum is 37.

The square root of 671542921 is about 25914.1451913815. The cubic root of 671542921 is about 875.7051930315.

The spelling of 671542921 in words is "six hundred seventy-one million, five hundred forty-two thousand, nine hundred twenty-one".