20421957600 has 1152 divisors, whose sum is σ = 87204418560. Its totient is φ = 4561920000.

The previous prime is 20421957559. The next prime is 20421957613. The reversal of 20421957600 is 675912402.

20421957600 is a `hidden beast` number, since 2 + 0 + 42 + 1 + 9 + 5 + 7 + 600 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 202197550 + ... + 202197650.

It is an arithmetic number, because the mean of its divisors is an integer number (75698280).

Almost surely, 2^20421957600 is an apocalyptic number.

20421957600 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 20421957600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43602209280).

20421957600 is an abundant number, since it is smaller than the sum of its proper divisors (66782460960).

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

20421957600 is a wasteful number, since it uses less digits than its factorization.

20421957600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 201 (or 182 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The spelling of 20421957600 in words is "twenty billion, four hundred twenty-one million, nine hundred fifty-seven thousand, six hundred".