20421812400 has 240 divisors, whose sum is σ = 71499138048. Its totient is φ = 4941440000.

The previous prime is 20421812399. The next prime is 20421812417. The reversal of 20421812400 is 421812402.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 9252097 + ... + 9254303.

Almost surely, 2^20421812400 is an apocalyptic number.

20421812400 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 20421812400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35749569024).

20421812400 is an abundant number, since it is smaller than the sum of its proper divisors (51077325648).

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

20421812400 is a wasteful number, since it uses less digits than its factorization.

20421812400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2940 (or 2929 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 24.

The spelling of 20421812400 in words is "twenty billion, four hundred twenty-one million, eight hundred twelve thousand, four hundred".