21121425340 has 24 divisors (see below), whose sum is σ = 45106775280. Its totient is φ = 8305373568.

The previous prime is 21121425307. The next prime is 21121425383. The reversal of 21121425340 is 4352412112.

It is a super-2 number, since 2×21121425340² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8948577 + ... + 8950936.

It is an arithmetic number, because the mean of its divisors is an integer number (1879448970).

Almost surely, 2^21121425340 is an apocalyptic number.

21121425340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21121425340 is an abundant number, since it is smaller than the sum of its proper divisors (23985349940).

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

21121425340 is a wasteful number, since it uses less digits than its factorization.

21121425340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17899581 (or 17899579 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 25.

Adding to 21121425340 its reverse (4352412112), we get a palindrome (25473837452).

The spelling of 21121425340 in words is "twenty-one billion, one hundred twenty-one million, four hundred twenty-five thousand, three hundred forty".