21210854357 has 36 divisors (see below), whose sum is σ = 27854477280. Its totient is φ = 15808998480.

The previous prime is 21210854339. The next prime is 21210854381. The reversal of 21210854357 is 75345801212.

It is not a de Polignac number, because 21210854357 - 2⁶ = 21210854293 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21210854357.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210854387) by changing a digit.

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 35 ways as a sum of consecutive naturals, for example, 424394 + ... + 471732.

It is an arithmetic number, because the mean of its divisors is an integer number (773735480).

Almost surely, 2^21210854357 is an apocalyptic number.

It is an amenable number.

21210854357 is a deficient number, since it is larger than the sum of its proper divisors (6643622923).

21210854357 is a wasteful number, since it uses less digits than its factorization.

21210854357 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47414 (or 47380 counting only the distinct ones).

The product of its (nonzero) digits is 67200, while the sum is 38.

The spelling of 21210854357 in words is "twenty-one billion, two hundred ten million, eight hundred fifty-four thousand, three hundred fifty-seven".