21465043500 has 96 divisors (see below), whose sum is σ = 62671085568. Its totient is φ = 5708913600.

The previous prime is 21465043493. The next prime is 21465043531. The reversal of 21465043500 is 534056412.

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

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 31 ways as a sum of consecutive naturals, for example, 555819 + ... + 593181.

It is an arithmetic number, because the mean of its divisors is an integer number (652823808).

Almost surely, 2^21465043500 is an apocalyptic number.

21465043500 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 21465043500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31335542784).

21465043500 is an abundant number, since it is smaller than the sum of its proper divisors (41206042068).

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

21465043500 is a wasteful number, since it uses less digits than its factorization.

21465043500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37768 (or 37756 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 30.

Adding to 21465043500 its reverse (534056412), we get a palindrome (21999099912).

The spelling of 21465043500 in words is "twenty-one billion, four hundred sixty-five million, forty-three thousand, five hundred".