21012011320 has 16 divisors (see below), whose sum is σ = 47277025560. Its totient is φ = 8404804512.

The previous prime is 21012011299. The next prime is 21012011347. The reversal of 21012011320 is 2311021012.

It is a self number, because there is not a number n which added to its sum of digits gives 21012011320.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 262650102 + ... + 262650181.

Almost surely, 2^21012011320 is an apocalyptic number.

21012011320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21012011320 is an abundant number, since it is smaller than the sum of its proper divisors (26265014240).

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

21012011320 is a wasteful number, since it uses less digits than its factorization.

21012011320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 525300294 (or 525300290 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 21012011320 its reverse (2311021012), we get a palindrome (23323032332).

The spelling of 21012011320 in words is "twenty-one billion, twelve million, eleven thousand, three hundred twenty".