21211220104 has 8 divisors (see below), whose sum is σ = 39771037710. Its totient is φ = 10605610048.

The previous prime is 21211220083. The next prime is 21211220111. The reversal of 21211220104 is 40102211212.

It can be written as a sum of positive squares in only one way, i.e., 11384463204 + 9826756900 = 106698^2 + 99130^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1325701249 + ... + 1325701264.

Almost surely, 2^21211220104 is an apocalyptic number.

It is an amenable number.

21211220104 is a deficient number, since it is larger than the sum of its proper divisors (18559817606).

21211220104 is a wasteful number, since it uses less digits than its factorization.

21211220104 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2651402519 (or 2651402515 counting only the distinct ones).

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

Adding to 21211220104 its reverse (40102211212), we get a palindrome (61313431316).

The spelling of 21211220104 in words is "twenty-one billion, two hundred eleven million, two hundred twenty thousand, one hundred four".