21121002135455 has 8 divisors (see below), whose sum is σ = 25346943272304. Its totient is φ = 16895641235200.

The previous prime is 21121002135397. The next prime is 21121002135503. The reversal of 21121002135455 is 55453120012112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21121002135455 - 2¹⁰ = 21121002134431 is a prime.

It is a Duffinian number.

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, 144979061 + ... + 145124670.

It is an arithmetic number, because the mean of its divisors is an integer number (3168367909038).

Almost surely, 2^{21121002135455} is an apocalyptic number.

21121002135455 is a deficient number, since it is larger than the sum of its proper divisors (4225941136849).

21121002135455 is a wasteful number, since it uses less digits than its factorization.

21121002135455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 290118297.

The product of its (nonzero) digits is 12000, while the sum is 32.

Adding to 21121002135455 its reverse (55453120012112), we get a palindrome (76574122147567).

The spelling of 21121002135455 in words is "twenty-one trillion, one hundred twenty-one billion, two million, one hundred thirty-five thousand, four hundred fifty-five".