6859981 has 2 divisors, whose sum is σ = 6859982. Its totient is φ = 6859980.

The previous prime is 6859973. The next prime is 6859991. The reversal of 6859981 is 1899586.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6584356 + 275625 = 2566^2 + 525^2 .

It is a cyclic number.

It is not a de Polignac number, because 6859981 - 2³ = 6859973 is a prime.

It is a super-2 number, since 2×6859981² = 94118678640722, which contains 22 as substring.

It is a plaindrome in base 16.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6859901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3429990 + 3429991.

It is an arithmetic number, because the mean of its divisors is an integer number (3429991).

Almost surely, 2^6859981 is an apocalyptic number.

6859981 is the 1657-th centered pentagonal number.

It is an amenable number.

6859981 is a deficient number, since it is larger than the sum of its proper divisors (1).

6859981 is an equidigital number, since it uses as much as digits as its factorization.

6859981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 155520, while the sum is 46.

The square root of 6859981 is about 2619.1565436224. The cubic root of 6859981 is about 190.0090577399.

The spelling of 6859981 in words is "six million, eight hundred fifty-nine thousand, nine hundred eighty-one".