21142122100 has 144 divisors (see below), whose sum is σ = 52412645376. Its totient is φ = 7327408000.

The previous prime is 21142122061. The next prime is 21142122139. The reversal of 21142122100 is 122124112.

It is an interprime number because it is at equal distance from previous prime (21142122061) and next prime (21142122139).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 7866957 + ... + 7869643.

It is an arithmetic number, because the mean of its divisors is an integer number (363976704).

Almost surely, 2^21142122100 is an apocalyptic number.

21142122100 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 21142122100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26206322688).

21142122100 is an abundant number, since it is smaller than the sum of its proper divisors (31270523276).

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

21142122100 is a wasteful number, since it uses less digits than its factorization.

21142122100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3046 (or 3039 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21142122100 its reverse (122124112), we get a palindrome (21264246212).

The spelling of 21142122100 in words is "twenty-one billion, one hundred forty-two million, one hundred twenty-two thousand, one hundred".