21121349740 has 96 divisors (see below), whose sum is σ = 46624241664. Its totient is φ = 8029082880.

The previous prime is 21121349737. The next prime is 21121349747. The reversal of 21121349740 is 4794312112.

It is a super-2 number, since 2×21121349740² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21121349696 and 21121349705.

It is not an unprimeable number, because it can be changed into a prime (21121349747) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 7314577 + ... + 7317463.

It is an arithmetic number, because the mean of its divisors is an integer number (485669184).

Almost surely, 2^21121349740 is an apocalyptic number.

21121349740 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 21121349740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23312120832).

21121349740 is an abundant number, since it is smaller than the sum of its proper divisors (25502891924).

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

21121349740 is a wasteful number, since it uses less digits than its factorization.

21121349740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3167 (or 3165 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 34.

The spelling of 21121349740 in words is "twenty-one billion, one hundred twenty-one million, three hundred forty-nine thousand, seven hundred forty".