21312511340 has 48 divisors (see below), whose sum is σ = 46004700000. Its totient is φ = 8287598592.

The previous prime is 21312511331. The next prime is 21312511369. The reversal of 21312511340 is 4311521312.

It is a super-3 number, since 3×21312511340³ (a number of 32 digits) contains 333 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 912731 + ... + 935789.

It is an arithmetic number, because the mean of its divisors is an integer number (958431250).

Almost surely, 2^21312511340 is an apocalyptic number.

21312511340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21312511340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23002350000).

21312511340 is an abundant number, since it is smaller than the sum of its proper divisors (24692188660).

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

21312511340 is a wasteful number, since it uses less digits than its factorization.

21312511340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24354 (or 24352 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 23.

The spelling of 21312511340 in words is "twenty-one billion, three hundred twelve million, five hundred eleven thousand, three hundred forty".