671649421 has 8 divisors (see below), whose sum is σ = 690444864. Its totient is φ = 653113440.

The previous prime is 671649409. The next prime is 671649469. The reversal of 671649421 is 124946176.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 671649421 - 2⁹ = 671648909 is a prime.

It is a super-2 number, since 2×671649421² = 902225889459270482, 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 (671649401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 59611 + ... + 69976.

It is an arithmetic number, because the mean of its divisors is an integer number (86305608).

Almost surely, 2^671649421 is an apocalyptic number.

It is an amenable number.

671649421 is a deficient number, since it is larger than the sum of its proper divisors (18795443).

671649421 is a wasteful number, since it uses less digits than its factorization.

671649421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129731.

The product of its digits is 72576, while the sum is 40.

The square root of 671649421 is about 25916.1999722181. The cubic root of 671649421 is about 875.7514832836.

The spelling of 671649421 in words is "six hundred seventy-one million, six hundred forty-nine thousand, four hundred twenty-one".