21222154100 has 36 divisors (see below), whose sum is σ = 52630943904. Its totient is φ = 7276166880.

The previous prime is 21222154091. The next prime is 21222154157. The reversal of 21222154100 is 145122212.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15157982 + ... + 15159381.

It is an arithmetic number, because the mean of its divisors is an integer number (1461970664).

Almost surely, 2^21222154100 is an apocalyptic number.

21222154100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21222154100 is an abundant number, since it is smaller than the sum of its proper divisors (31408789804).

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

21222154100 is a wasteful number, since it uses less digits than its factorization.

21222154100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30317384 (or 30317377 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 20.

Adding to 21222154100 its reverse (145122212), we get a palindrome (21367276312).

The spelling of 21222154100 in words is "twenty-one billion, two hundred twenty-two million, one hundred fifty-four thousand, one hundred".