21030312022021 has 4 divisors (see below), whose sum is σ = 21033292093132. Its totient is φ = 21027331950912.

The previous prime is 21030312021973. The next prime is 21030312022043. The reversal of 21030312022021 is 12022021303012.

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 11099651844996 + 9930660177025 = 3331614^2 + 3151295^2 .

It is a cyclic number.

It is not a de Polignac number, because 21030312022021 - 2²³ = 21030303633413 is a prime.

It is a super-2 number, since 2×21030312022021² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21030312022021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21030312022121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1490024970 + ... + 1490039083.

It is an arithmetic number, because the mean of its divisors is an integer number (5258323023283).

Almost surely, 2^{21030312022021} is an apocalyptic number.

It is an amenable number.

21030312022021 is a deficient number, since it is larger than the sum of its proper divisors (2980071111).

21030312022021 is an equidigital number, since it uses as much as digits as its factorization.

21030312022021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2980071110.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 21030312022021 its reverse (12022021303012), we get a palindrome (33052333325033).

The spelling of 21030312022021 in words is "twenty-one trillion, thirty billion, three hundred twelve million, twenty-two thousand, twenty-one".