21021212195 has 16 divisors (see below), whose sum is σ = 25283270880. Its totient is φ = 16778471424.

The previous prime is 21021212141. The next prime is 21021212221. The reversal of 21021212195 is 59121212012.

It is a cyclic number.

It is not a de Polignac number, because 21021212195 - 2¹⁰ = 21021211171 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7151036 + ... + 7153974.

It is an arithmetic number, because the mean of its divisors is an integer number (1580204430).

Almost surely, 2^21021212195 is an apocalyptic number.

21021212195 is a deficient number, since it is larger than the sum of its proper divisors (4262058685).

21021212195 is a wasteful number, since it uses less digits than its factorization.

21021212195 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5734.

The product of its (nonzero) digits is 720, while the sum is 26.

The spelling of 21021212195 in words is "twenty-one billion, twenty-one million, two hundred twelve thousand, one hundred ninety-five".