21012802 has 16 divisors (see below), whose sum is σ = 32127480. Its totient is φ = 10305792.

The previous prime is 21012779. The next prime is 21012821. The reversal of 21012802 is 20821012.

It can be written as a sum of positive squares in 4 ways, for example, as 8346321 + 12666481 = 2889^2 + 3559^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24208 + ... + 25060.

Almost surely, 2^21012802 is an apocalyptic number.

21012802 is a deficient number, since it is larger than the sum of its proper divisors (11114678).

21012802 is a wasteful number, since it uses less digits than its factorization.

21012802 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1077.

The product of its (nonzero) digits is 64, while the sum is 16.

The square root of 21012802 is about 4583.9722948552. The cubic root of 21012802 is about 275.9484693406.

Adding to 21012802 its reverse (20821012), we get a palindrome (41833814).

The spelling of 21012802 in words is "twenty-one million, twelve thousand, eight hundred two".