2121403653644 has 192 divisors, whose sum is σ = 4433213030400. Its totient is φ = 877538188800.

The previous prime is 2121403653637. The next prime is 2121403653659. The reversal of 2121403653644 is 4463563041212.

It is a super-2 number, since 2×2121403653644² (a number of 25 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3728301392 + ... + 3728301960.

It is an arithmetic number, because the mean of its divisors is an integer number (23089651200).

Almost surely, 2^{2121403653644} is an apocalyptic number.

It is an amenable number.

2121403653644 is an abundant number, since it is smaller than the sum of its proper divisors (2311809376756).

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

2121403653644 is a wasteful number, since it uses less digits than its factorization.

2121403653644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1444 (or 1442 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 41.

Adding to 2121403653644 its reverse (4463563041212), we get a palindrome (6584966694856).

The spelling of 2121403653644 in words is "two trillion, one hundred twenty-one billion, four hundred three million, six hundred fifty-three thousand, six hundred forty-four".