21022010100 has 864 divisors, whose sum is σ = 85989496320. Its totient is φ = 4176506880.

The previous prime is 21022010099. The next prime is 21022010101. The reversal of 21022010100 is 101022012.

It is an interprime number because it is at equal distance from previous prime (21022010099) and next prime (21022010101).

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21022010101) by changing a digit.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 125880217 + ... + 125880383.

It is an arithmetic number, because the mean of its divisors is an integer number (99524880).

Almost surely, 2^21022010100 is an apocalyptic number.

21022010100 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 21022010100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42994748160).

21022010100 is an abundant number, since it is smaller than the sum of its proper divisors (64967486220).

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

21022010100 is a wasteful number, since it uses less digits than its factorization.

21022010100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 289 (or 279 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 21022010100 its reverse (101022012), we get a palindrome (21123032112).

The spelling of 21022010100 in words is "twenty-one billion, twenty-two million, ten thousand, one hundred".