21605311422 has 12 divisors (see below), whose sum is σ = 46811508120. Its totient is φ = 7201770468.

The previous prime is 21605311417. The next prime is 21605311423. The reversal of 21605311422 is 22411350612.

21605311422 is a `hidden beast` number, since 2 + 1 + 605 + 3 + 11 + 42 + 2 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21605311423) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 600147522 + ... + 600147557.

It is an arithmetic number, because the mean of its divisors is an integer number (3900959010).

Almost surely, 2^21605311422 is an apocalyptic number.

21605311422 is an abundant number, since it is smaller than the sum of its proper divisors (25206196698).

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

21605311422 is a wasteful number, since it uses less digits than its factorization.

21605311422 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1200295087 (or 1200295084 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

It can be divided in two parts, 216053 and 11422, that added together give a triangular number (227475 = T₆₇₄).

The spelling of 21605311422 in words is "twenty-one billion, six hundred five million, three hundred eleven thousand, four hundred twenty-two".