21503623680 has 1920 divisors, whose sum is σ = 105894936576. Its totient is φ = 3892838400.

The previous prime is 21503623667. The next prime is 21503623699. The reversal of 21503623680 is 8632630512.

It is a happy number.

21503623680 is a `hidden beast` number, since 21 + 5 + 0 + 3 + 623 + 6 + 8 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1920).

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 693665265 + ... + 693665295.

Almost surely, 2^21503623680 is an apocalyptic number.

21503623680 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 21503623680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (52947468288).

21503623680 is an abundant number, since it is smaller than the sum of its proper divisors (84391312896).

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

21503623680 is a wasteful number, since it uses less digits than its factorization.

21503623680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118 (or 99 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The spelling of 21503623680 in words is "twenty-one billion, five hundred three million, six hundred twenty-three thousand, six hundred eighty".