6471659921 has 4 divisors (see below), whose sum is σ = 6532142832. Its totient is φ = 6411177012.

The previous prime is 6471659893. The next prime is 6471659933. The reversal of 6471659921 is 1299561746.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6471659921 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 6471659921.

It is not an unprimeable number, because it can be changed into a prime (6471653921) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30241295 + ... + 30241508.

It is an arithmetic number, because the mean of its divisors is an integer number (1633035708).

Almost surely, 2^6471659921 is an apocalyptic number.

It is an amenable number.

6471659921 is a deficient number, since it is larger than the sum of its proper divisors (60482911).

6471659921 is a wasteful number, since it uses less digits than its factorization.

6471659921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60482910.

The product of its digits is 816480, while the sum is 50.

The square root of 6471659921 is about 80446.6277789194. The cubic root of 6471659921 is about 1863.5393279457.

The spelling of 6471659921 in words is "six billion, four hundred seventy-one million, six hundred fifty-nine thousand, nine hundred twenty-one".