100821420 has 288 divisors, whose sum is σ = 377395200. Its totient is φ = 21732480.

The previous prime is 100821377. The next prime is 100821421. The reversal of 100821420 is 24128001.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 100821393 and 100821402.

It is not an unprimeable number, because it can be changed into a prime (100821421) by changing a digit.

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 95 ways as a sum of consecutive naturals, for example, 1419985 + ... + 1420055.

It is an arithmetic number, because the mean of its divisors is an integer number (1310400).

Almost surely, 2^100821420 is an apocalyptic number.

100821420 is a gapful number since it is divisible by the number (10) 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 100821420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (188697600).

100821420 is an abundant number, since it is smaller than the sum of its proper divisors (276573780).

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

100821420 is a wasteful number, since it uses less digits than its factorization.

100821420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130 (or 111 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The square root of 100821420 is about 10040.9870032781. The cubic root of 100821420 is about 465.4263173179.

Adding to 100821420 its reverse (24128001), we get a palindrome (124949421).

The spelling of 100821420 in words is "one hundred million, eight hundred twenty-one thousand, four hundred twenty".