6997581 has 12 divisors (see below), whose sum is σ = 10137660. Its totient is φ = 4651200.

The previous prime is 6997579. The next prime is 6997597. The reversal of 6997581 is 1857996.

6997581 is a `hidden beast` number, since 69 + 9 + 7 + 581 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 3481956 + 3515625 = 1866^2 + 1875^2 .

It is not a de Polignac number, because 6997581 - 2¹ = 6997579 is a prime.

It is a super-2 number, since 2×6997581² = 97932279703122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6997531) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2731 + ... + 4631.

It is an arithmetic number, because the mean of its divisors is an integer number (844805).

Almost surely, 2^6997581 is an apocalyptic number.

It is an amenable number.

6997581 is a deficient number, since it is larger than the sum of its proper divisors (3140079).

6997581 is a wasteful number, since it uses less digits than its factorization.

6997581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2316 (or 2313 counting only the distinct ones).

The product of its digits is 136080, while the sum is 45.

The square root of 6997581 is about 2645.2941235333. The cubic root of 6997581 is about 191.2710805931.

The spelling of 6997581 in words is "six million, nine hundred ninety-seven thousand, five hundred eighty-one".