21123117340 has 36 divisors (see below), whose sum is σ = 48033226584. Its totient is φ = 7799303616.

The previous prime is 21123117293. The next prime is 21123117419. The reversal of 21123117340 is 4371132112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3121342 + ... + 3128101.

It is an arithmetic number, because the mean of its divisors is an integer number (1334256294).

Almost surely, 2^21123117340 is an apocalyptic number.

21123117340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21123117340 is an abundant number, since it is smaller than the sum of its proper divisors (26910109244).

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

21123117340 is a wasteful number, since it uses less digits than its factorization.

21123117340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6249478 (or 6249463 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 25.

Adding to 21123117340 its reverse (4371132112), we get a palindrome (25494249452).

The spelling of 21123117340 in words is "twenty-one billion, one hundred twenty-three million, one hundred seventeen thousand, three hundred forty".