21212475905 has 8 divisors (see below), whose sum is σ = 25457064000. Its totient is φ = 16968585456.

The previous prime is 21212475841. The next prime is 21212475913. The reversal of 21212475905 is 50957421212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21212475905 - 2⁶ = 21212475841 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 105005 + ... + 231194.

It is an arithmetic number, because the mean of its divisors is an integer number (3182133000).

Almost surely, 2^21212475905 is an apocalyptic number.

It is an amenable number.

21212475905 is a deficient number, since it is larger than the sum of its proper divisors (4244588095).

21212475905 is a wasteful number, since it uses less digits than its factorization.

21212475905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 348823.

The product of its (nonzero) digits is 50400, while the sum is 38.

The spelling of 21212475905 in words is "twenty-one billion, two hundred twelve million, four hundred seventy-five thousand, nine hundred five".