21002122122140 has 96 divisors (see below), whose sum is σ = 46872743843520. Its totient is φ = 7889530650624.

The previous prime is 21002122122133. The next prime is 21002122122167. The reversal of 21002122122140 is 4122122120012.

It is a happy number.

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 polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 70820252 + ... + 71116188.

It is an arithmetic number, because the mean of its divisors is an integer number (488257748370).

Almost surely, 2^{21002122122140} is an apocalyptic number.

21002122122140 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 21002122122140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23436371921760).

21002122122140 is an abundant number, since it is smaller than the sum of its proper divisors (25870621721380).

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

21002122122140 is a wasteful number, since it uses less digits than its factorization.

21002122122140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 299319 (or 299317 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 20.

Adding to 21002122122140 its reverse (4122122120012), we get a palindrome (25124244242152).

The spelling of 21002122122140 in words is "twenty-one trillion, two billion, one hundred twenty-two million, one hundred twenty-two thousand, one hundred forty".