21211220204 has 6 divisors (see below), whose sum is σ = 37119635364. Its totient is φ = 10605610100.

The previous prime is 21211220183. The next prime is 21211220227. The reversal of 21211220204 is 40202211212.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2651402522 + ... + 2651402529.

It is an arithmetic number, because the mean of its divisors is an integer number (6186605894).

Almost surely, 2^21211220204 is an apocalyptic number.

It is an amenable number.

21211220204 is a deficient number, since it is larger than the sum of its proper divisors (15908415160).

21211220204 is a wasteful number, since it uses less digits than its factorization.

21211220204 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5302805055 (or 5302805053 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21211220204 its reverse (40202211212), we get a palindrome (61413431416).

The spelling of 21211220204 in words is "twenty-one billion, two hundred eleven million, two hundred twenty thousand, two hundred four".