6985216581 has 16 divisors (see below), whose sum is σ = 11270265984. Its totient is φ = 3756754944.

The previous prime is 6985216561. The next prime is 6985216583. The reversal of 6985216581 is 1856125896.

It is not a de Polignac number, because 6985216581 - 2⁵ = 6985216549 is a prime.

It is a super-2 number, since 2×6985216581² = 97586501366954659122, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6985216583) 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, 9782860 + ... + 9783573.

It is an arithmetic number, because the mean of its divisors is an integer number (704391624).

Almost surely, 2^6985216581 is an apocalyptic number.

It is an amenable number.

6985216581 is a deficient number, since it is larger than the sum of its proper divisors (4285049403).

6985216581 is a wasteful number, since it uses less digits than its factorization.

6985216581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19566460.

The product of its digits is 1036800, while the sum is 51.

The square root of 6985216581 is about 83577.6081316042. The cubic root of 6985216581 is about 1911.5835830255.

The spelling of 6985216581 in words is "six billion, nine hundred eighty-five million, two hundred sixteen thousand, five hundred eighty-one".