20983993453 has 4 divisors (see below), whose sum is σ = 21059748220. Its totient is φ = 20908238688.

The previous prime is 20983993439. The next prime is 20983993463. The reversal of 20983993453 is 35439938902.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 35439938902 = 2 ⋅17719969451.

It can be written as a sum of positive squares in 2 ways, for example, as 13493610244 + 7490383209 = 116162^2 + 86547^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20983993453 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20983993394 and 20983993403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20983993463) 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 3 ways as a sum of consecutive naturals, for example, 37876968 + ... + 37877521.

It is an arithmetic number, because the mean of its divisors is an integer number (5264937055).

Almost surely, 2^20983993453 is an apocalyptic number.

It is an amenable number.

20983993453 is a deficient number, since it is larger than the sum of its proper divisors (75754767).

20983993453 is an equidigital number, since it uses as much as digits as its factorization.

20983993453 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75754766.

The product of its (nonzero) digits is 6298560, while the sum is 55.

The spelling of 20983993453 in words is "twenty billion, nine hundred eighty-three million, nine hundred ninety-three thousand, four hundred fifty-three".