21212332320 has 96 divisors (see below), whose sum is σ = 66841467840. Its totient is φ = 5654707200.

The previous prime is 21212332313. The next prime is 21212332321. The reversal of 21212332320 is 2323321212.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (96).

It is not an unprimeable number, because it can be changed into a prime (21212332321) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1939026 + ... + 1949934.

It is an arithmetic number, because the mean of its divisors is an integer number (696265290).

Almost surely, 2^21212332320 is an apocalyptic number.

21212332320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21212332320 is an abundant number, since it is smaller than the sum of its proper divisors (45629135520).

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

21212332320 is a wasteful number, since it uses less digits than its factorization.

21212332320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14978 (or 14970 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 21.

Adding to 21212332320 its reverse (2323321212), we get a palindrome (23535653532).

The spelling of 21212332320 in words is "twenty-one billion, two hundred twelve million, three hundred thirty-two thousand, three hundred twenty".