21312121030320 has 80 divisors (see below), whose sum is σ = 68940078481152. Its totient is φ = 5436135217920.

The previous prime is 21312121030303. The next prime is 21312121030337. The reversal of 21312121030320 is 2303012121312.

It is an interprime number because it is at equal distance from previous prime (21312121030303) and next prime (21312121030337).

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-3 number, since 3×21312121030320³ (a number of 41 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1930440226 + ... + 1930451265.

Almost surely, 2^{21312121030320} is an apocalyptic number.

21312121030320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21312121030320 is an abundant number, since it is smaller than the sum of its proper divisors (47627957450832).

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

21312121030320 is a wasteful number, since it uses less digits than its factorization.

21312121030320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3860891530 (or 3860891524 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 21.

Adding to 21312121030320 its reverse (2303012121312), we get a palindrome (23615133151632).

The spelling of 21312121030320 in words is "twenty-one trillion, three hundred twelve billion, one hundred twenty-one million, thirty thousand, three hundred twenty".