21352305540 has 96 divisors (see below), whose sum is σ = 61516070784. Its totient is φ = 5530455040.

The previous prime is 21352305503. The next prime is 21352305587. The reversal of 21352305540 is 4550325312.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 21352305498 and 21352305507.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 539302 + ... + 577538.

It is an arithmetic number, because the mean of its divisors is an integer number (640792404).

Almost surely, 2^21352305540 is an apocalyptic number.

21352305540 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 21352305540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30758035392).

21352305540 is an abundant number, since it is smaller than the sum of its proper divisors (40163765244).

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

21352305540 is a wasteful number, since it uses less digits than its factorization.

21352305540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38517 (or 38515 counting only the distinct ones).

The product of its (nonzero) digits is 18000, while the sum is 30.

The spelling of 21352305540 in words is "twenty-one billion, three hundred fifty-two million, three hundred five thousand, five hundred forty".