21231422555 has 16 divisors (see below), whose sum is σ = 29129877504. Its totient is φ = 14552440800.

The previous prime is 21231422543. The next prime is 21231422557. The reversal of 21231422555 is 55522413212.

It is not a de Polignac number, because 21231422555 - 2⁴ = 21231422539 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21231422557) 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, 46727 + ... + 211296.

It is an arithmetic number, because the mean of its divisors is an integer number (1820617344).

Almost surely, 2^21231422555 is an apocalyptic number.

21231422555 is a deficient number, since it is larger than the sum of its proper divisors (7898454949).

21231422555 is a wasteful number, since it uses less digits than its factorization.

21231422555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 260386.

The product of its digits is 24000, while the sum is 32.

Adding to 21231422555 its reverse (55522413212), we get a palindrome (76753835767).

The spelling of 21231422555 in words is "twenty-one billion, two hundred thirty-one million, four hundred twenty-two thousand, five hundred fifty-five".