21305362540 has 192 divisors, whose sum is σ = 59643537408. Its totient is φ = 6188544000.

The previous prime is 21305362499. The next prime is 21305362571. The reversal of 21305362540 is 4526350312.

It is a happy 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 63 ways as a sum of consecutive naturals, for example, 2692590 + ... + 2700490.

It is an arithmetic number, because the mean of its divisors is an integer number (310643424).

Almost surely, 2^21305362540 is an apocalyptic number.

21305362540 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 21305362540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29821768704).

21305362540 is an abundant number, since it is smaller than the sum of its proper divisors (38338174868).

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

21305362540 is a wasteful number, since it uses less digits than its factorization.

21305362540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8048 (or 8046 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 31.

The spelling of 21305362540 in words is "twenty-one billion, three hundred five million, three hundred sixty-two thousand, five hundred forty".