21234105412 has 12 divisors (see below), whose sum is σ = 40018121836. Its totient is φ = 9800356320.

The previous prime is 21234105377. The next prime is 21234105421. The reversal of 21234105412 is 21450143212.

It can be written as a sum of positive squares in 2 ways, for example, as 12654900036 + 8579205376 = 112494^2 + 92624^2 .

It is an alternating number because its digits alternate between even and odd.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 204174039 + ... + 204174142.

Almost surely, 2^21234105412 is an apocalyptic number.

It is an amenable number.

21234105412 is a deficient number, since it is larger than the sum of its proper divisors (18784016424).

21234105412 is a wasteful number, since it uses less digits than its factorization.

21234105412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 408348198 (or 408348196 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 25.

Adding to 21234105412 its reverse (21450143212), we get a palindrome (42684248624).

The spelling of 21234105412 in words is "twenty-one billion, two hundred thirty-four million, one hundred five thousand, four hundred twelve".