21681062 has 8 divisors (see below), whose sum is σ = 35023296. Its totient is φ = 10006632.

The previous prime is 21681061. The next prime is 21681091. The reversal of 21681062 is 26018612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Harshad number since it is a multiple of its sum of digits (26), and also a Moran number because the ratio is a prime number: 833887 = 21681062 / (2 + 1 + 6 + 8 + 1 + 0 + 6 + 2).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21681061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 416918 + ... + 416969.

It is an arithmetic number, because the mean of its divisors is an integer number (4377912).

Almost surely, 2^21681062 is an apocalyptic number.

21681062 is a deficient number, since it is larger than the sum of its proper divisors (13342234).

21681062 is a wasteful number, since it uses less digits than its factorization.

21681062 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 833902.

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 21681062 is about 4656.2927313475. The cubic root of 21681062 is about 278.8432807319.

Adding to 21681062 its reverse (26018612), we get a palindrome (47699674).

The spelling of 21681062 in words is "twenty-one million, six hundred eighty-one thousand, sixty-two".