6721531 has 8 divisors (see below), whose sum is σ = 6935760. Its totient is φ = 6509088.

The previous prime is 6721523. The next prime is 6721541. The reversal of 6721531 is 1351276.

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 6721531 - 2³ = 6721523 is a prime.

It is a super-2 number, since 2×6721531² = 90357957967922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 6721496 and 6721505.

It is not an unprimeable number, because it can be changed into a prime (6721501) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14160 + ... + 14626.

It is an arithmetic number, because the mean of its divisors is an integer number (866970).

Almost surely, 2^6721531 is an apocalyptic number.

6721531 is a deficient number, since it is larger than the sum of its proper divisors (214229).

6721531 is a wasteful number, since it uses less digits than its factorization.

6721531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 893.

The product of its digits is 1260, while the sum is 25.

The square root of 6721531 is about 2592.5915605818. The cubic root of 6721531 is about 188.7220890560.

The spelling of 6721531 in words is "six million, seven hundred twenty-one thousand, five hundred thirty-one".