21462211561 has 16 divisors (see below), whose sum is σ = 26238836736. Its totient is φ = 17135548416.

The previous prime is 21462211549. The next prime is 21462211591. The reversal of 21462211561 is 16511226412.

It is a happy number.

It is not a de Polignac number, because 21462211561 - 2⁹ = 21462211049 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21462211531) 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, 918121 + ... + 941206.

It is an arithmetic number, because the mean of its divisors is an integer number (1639927296).

Almost surely, 2^21462211561 is an apocalyptic number.

It is an amenable number.

21462211561 is a deficient number, since it is larger than the sum of its proper divisors (4776625175).

21462211561 is a wasteful number, since it uses less digits than its factorization.

21462211561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1859448.

The product of its digits is 5760, while the sum is 31.

Adding to 21462211561 its reverse (16511226412), we get a palindrome (37973437973).

The spelling of 21462211561 in words is "twenty-one billion, four hundred sixty-two million, two hundred eleven thousand, five hundred sixty-one".