21855708413 has 16 divisors (see below), whose sum is σ = 27322957824. Its totient is φ = 16983995760.

The previous prime is 21855708397. The next prime is 21855708449. The reversal of 21855708413 is 31480755812.

It is a cyclic number.

It is not a de Polignac number, because 21855708413 - 2⁴ = 21855708397 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21855708313) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 358445 + ... + 414962.

It is an arithmetic number, because the mean of its divisors is an integer number (1707684864).

Almost surely, 2^21855708413 is an apocalyptic number.

It is an amenable number.

21855708413 is a deficient number, since it is larger than the sum of its proper divisors (5467249411).

21855708413 is a wasteful number, since it uses less digits than its factorization.

21855708413 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 773792.

The product of its (nonzero) digits is 268800, while the sum is 44.

The spelling of 21855708413 in words is "twenty-one billion, eight hundred fifty-five million, seven hundred eight thousand, four hundred thirteen".