21103672500 has 480 divisors, whose sum is σ = 73969822080. Its totient is φ = 5181696000.

The previous prime is 21103672493. The next prime is 21103672507. The reversal of 21103672500 is 527630112.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21103672493) and next prime (21103672507).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21103672507) by changing a digit.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 60817327 + ... + 60817673.

It is an arithmetic number, because the mean of its divisors is an integer number (154103796).

Almost surely, 2^21103672500 is an apocalyptic number.

21103672500 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 21103672500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36984911040).

21103672500 is an abundant number, since it is smaller than the sum of its proper divisors (52866149580).

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

21103672500 is a wasteful number, since it uses less digits than its factorization.

21103672500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 450 (or 427 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 27.

The spelling of 21103672500 in words is "twenty-one billion, one hundred three million, six hundred seventy-two thousand, five hundred".