21203231916349 has 12 divisors (see below), whose sum is σ = 24684923493084. Its totient is φ = 18159506576064.

The previous prime is 21203231916323. The next prime is 21203231916353. The reversal of 21203231916349 is 94361913230212.

It can be written as a sum of positive squares in 2 ways, for example, as 15668890976025 + 5534340940324 = 3958395^2 + 2352518^2 .

It is not a de Polignac number, because 21203231916349 - 2³⁹ = 20653476102461 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21203231916299 and 21203231916308.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21203231913349) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 174846024 + ... + 174967249.

It is an arithmetic number, because the mean of its divisors is an integer number (2057076957757).

Almost surely, 2^{21203231916349} is an apocalyptic number.

It is an amenable number.

21203231916349 is a deficient number, since it is larger than the sum of its proper divisors (3481691576735).

21203231916349 is a wasteful number, since it uses less digits than its factorization.

21203231916349 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 349814524 (or 349814517 counting only the distinct ones).

The product of its (nonzero) digits is 419904, while the sum is 46.

The spelling of 21203231916349 in words is "twenty-one trillion, two hundred three billion, two hundred thirty-one million, nine hundred sixteen thousand, three hundred forty-nine".