21254102100 has 432 divisors, whose sum is σ = 87949120896. Its totient is φ = 4156416000.

The previous prime is 21254102081. The next prime is 21254102119. The reversal of 21254102100 is 120145212.

21254102100 is a `hidden beast` number, since 21 + 2 + 541 + 0 + 2 + 100 = 666.

It is an interprime number because it is at equal distance from previous prime (21254102081) and next prime (21254102119).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 1169080 + ... + 1187120.

It is an arithmetic number, because the mean of its divisors is an integer number (203585928).

Almost surely, 2^21254102100 is an apocalyptic number.

21254102100 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 21254102100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43974560448).

21254102100 is an abundant number, since it is smaller than the sum of its proper divisors (66695018796).

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

21254102100 is a wasteful number, since it uses less digits than its factorization.

21254102100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18096 (or 18086 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

Adding to 21254102100 its reverse (120145212), we get a palindrome (21374247312).

The spelling of 21254102100 in words is "twenty-one billion, two hundred fifty-four million, one hundred two thousand, one hundred".