6905721 has 16 divisors (see below), whose sum is σ = 9800000. Its totient is φ = 4313088.

The previous prime is 6905713. The next prime is 6905729. The reversal of 6905721 is 1275096.

It is an interprime number because it is at equal distance from previous prime (6905713) and next prime (6905729).

It is not a de Polignac number, because 6905721 - 2³ = 6905713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6905729) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4905 + ... + 6153.

It is an arithmetic number, because the mean of its divisors is an integer number (612500).

Almost surely, 2^6905721 is an apocalyptic number.

It is an amenable number.

6905721 is a deficient number, since it is larger than the sum of its proper divisors (2894279).

6905721 is a wasteful number, since it uses less digits than its factorization.

6905721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1368.

The product of its (nonzero) digits is 3780, while the sum is 30.

The square root of 6905721 is about 2627.8738554200. The cubic root of 6905721 is about 190.4304276778.

It can be divided in two parts, 6905 and 721, that added together give a triangular number (7626 = T₁₂₃).

The spelling of 6905721 in words is "six million, nine hundred five thousand, seven hundred twenty-one".