20851004 has 12 divisors (see below), whose sum is σ = 36595104. Its totient is φ = 10395264.

The previous prime is 20850979. The next prime is 20851007. The reversal of 20851004 is 40015802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20851007) 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, 5972 + ... + 8795.

It is an arithmetic number, because the mean of its divisors is an integer number (3049592).

Almost surely, 2^20851004 is an apocalyptic number.

It is an amenable number.

20851004 is a deficient number, since it is larger than the sum of its proper divisors (15744100).

20851004 is a wasteful number, since it uses less digits than its factorization.

20851004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15124 (or 15122 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 20.

The square root of 20851004 is about 4566.2899601317. The cubic root of 20851004 is about 275.2383784305.

Adding to 20851004 its reverse (40015802), we get a palindrome (60866806).

The spelling of 20851004 in words is "twenty million, eight hundred fifty-one thousand, four".