6721971 has 4 divisors (see below), whose sum is σ = 8962632. Its totient is φ = 4481312.

The previous prime is 6721969. The next prime is 6721973. The reversal of 6721971 is 1791276.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (6721969) and next prime (6721973).

It is a cyclic number.

It is not a de Polignac number, because 6721971 - 2¹ = 6721969 is a prime.

It is a D-number.

It is not an unprimeable number, because it can be changed into a prime (6721973) 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, 1120326 + ... + 1120331.

It is an arithmetic number, because the mean of its divisors is an integer number (2240658).

Almost surely, 2^6721971 is an apocalyptic number.

6721971 is a deficient number, since it is larger than the sum of its proper divisors (2240661).

6721971 is a wasteful number, since it uses less digits than its factorization.

6721971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2240660.

The product of its digits is 5292, while the sum is 33.

The square root of 6721971 is about 2592.6764163698. The cubic root of 6721971 is about 188.7262069624.

The spelling of 6721971 in words is "six million, seven hundred twenty-one thousand, nine hundred seventy-one".