21213301993812 has 18 divisors (see below), whose sum is σ = 53622513373338. Its totient is φ = 7071100664592.

The previous prime is 21213301993811. The next prime is 21213301993831. The reversal of 21213301993812 is 21839910331212.

21213301993812 is a `hidden beast` number, since 2 + 1 + 213 + 301 + 99 + 38 + 12 = 666.

It can be written as a sum of positive squares in only one way, i.e., 12474148079376 + 8739153914436 = 3531876^2 + 2956206^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21213301993811) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 294629194323 + ... + 294629194394.

It is an arithmetic number, because the mean of its divisors is an integer number (2979028520741).

Almost surely, 2^{21213301993812} is an apocalyptic number.

It is an amenable number.

21213301993812 is an abundant number, since it is smaller than the sum of its proper divisors (32409211379526).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21213301993812 is a wasteful number, since it uses less digits than its factorization.

21213301993812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 589258388727 (or 589258388722 counting only the distinct ones).

The product of its (nonzero) digits is 139968, while the sum is 45.

The spelling of 21213301993812 in words is "twenty-one trillion, two hundred thirteen billion, three hundred one million, nine hundred ninety-three thousand, eight hundred twelve".