21211212104 has 16 divisors (see below), whose sum is σ = 39773697900. Its totient is φ = 10604892672.

The previous prime is 21211212083. The next prime is 21211212107. The reversal of 21211212104 is 40121211212.

It can be written as a sum of positive squares in 2 ways, for example, as 20996589604 + 214622500 = 144902^2 + 14650^2 .

It is a super-2 number, since 2×21211212104² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21211212107) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49964 + ... + 211940.

Almost surely, 2^21211212104 is an apocalyptic number.

It is an amenable number.

21211212104 is a deficient number, since it is larger than the sum of its proper divisors (18562485796).

21211212104 is a wasteful number, since it uses less digits than its factorization.

21211212104 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178352 (or 178348 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21211212104 its reverse (40121211212), we get a palindrome (61332423316).

The spelling of 21211212104 in words is "twenty-one billion, two hundred eleven million, two hundred twelve thousand, one hundred four".