6981221 has 12 divisors (see below), whose sum is σ = 7653060. Its totient is φ = 6364800.

The previous prime is 6981211. The next prime is 6981229. The reversal of 6981221 is 1221896.

It can be written as a sum of positive squares in 6 ways, for example, as 148225 + 6832996 = 385^2 + 2614^2 .

It is not a de Polignac number, because 6981221 - 2⁶ = 6981157 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6981229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16865 + ... + 17273.

It is an arithmetic number, because the mean of its divisors is an integer number (637755).

Almost surely, 2^6981221 is an apocalyptic number.

It is an amenable number.

6981221 is a deficient number, since it is larger than the sum of its proper divisors (671839).

6981221 is a wasteful number, since it uses less digits than its factorization.

6981221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 536 (or 523 counting only the distinct ones).

The product of its digits is 1728, while the sum is 29.

The square root of 6981221 is about 2642.2000302778. The cubic root of 6981221 is about 191.1219034853.

It can be divided in two parts, 698 and 1221, that multiplied together give a palindrome (852258).

The spelling of 6981221 in words is "six million, nine hundred eighty-one thousand, two hundred twenty-one".