6721947 has 20 divisors (see below), whose sum is σ = 10369216. Its totient is φ = 4335120.

The previous prime is 6721943. The next prime is 6721951. The reversal of 6721947 is 7491276.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (6721943) and next prime (6721951).

It is not a de Polignac number, because 6721947 - 2² = 6721943 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6721943) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1173 + ... + 3849.

Almost surely, 2^6721947 is an apocalyptic number.

6721947 is a deficient number, since it is larger than the sum of its proper divisors (3647269).

6721947 is a wasteful number, since it uses less digits than its factorization.

6721947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2720 (or 2711 counting only the distinct ones).

The product of its digits is 21168, while the sum is 36.

The square root of 6721947 is about 2592.6717879439. The cubic root of 6721947 is about 188.7259823540.

The spelling of 6721947 in words is "six million, seven hundred twenty-one thousand, nine hundred forty-seven".