12121437840 has 40 divisors (see below), whose sum is σ = 37576458048. Its totient is φ = 3232383360.

The previous prime is 12121437827. The next prime is 12121437857. The reversal of 12121437840 is 4873412121.

It is a tau number, because it is divible by the number of its divisors (40).

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, 25252756 + ... + 25253235.

Almost surely, 2^12121437840 is an apocalyptic number.

12121437840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12121437840 is an abundant number, since it is smaller than the sum of its proper divisors (25455020208).

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

12121437840 is a wasteful number, since it uses less digits than its factorization.

12121437840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50506007 (or 50506001 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 33.

Adding to 12121437840 its reverse (4873412121), we get a palindrome (16994849961).

The spelling of 12121437840 in words is "twelve billion, one hundred twenty-one million, four hundred thirty-seven thousand, eight hundred forty".