21030213493 has 4 divisors (see below), whose sum is σ = 21427010028. Its totient is φ = 20633416960.

The previous prime is 21030213481. The next prime is 21030213499. The reversal of 21030213493 is 39431203012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 18159718564 + 2870494929 = 134758^2 + 53577^2 .

It is a cyclic number.

It is not a de Polignac number, because 21030213493 - 2³³ = 12440278901 is a prime.

It is a super-2 number, since 2×21030213493² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21030213499) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 198398188 + ... + 198398293.

It is an arithmetic number, because the mean of its divisors is an integer number (5356752507).

Almost surely, 2^21030213493 is an apocalyptic number.

It is an amenable number.

21030213493 is a deficient number, since it is larger than the sum of its proper divisors (396796535).

21030213493 is an equidigital number, since it uses as much as digits as its factorization.

21030213493 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 396796534.

The product of its (nonzero) digits is 3888, while the sum is 28.

The spelling of 21030213493 in words is "twenty-one billion, thirty million, two hundred thirteen thousand, four hundred ninety-three".