21323206155 has 16 divisors (see below), whose sum is σ = 34148542464. Its totient is φ = 11361905760.

The previous prime is 21323206127. The next prime is 21323206169. The reversal of 21323206155 is 55160232312.

It is not a de Polignac number, because 21323206155 - 2⁸ = 21323205899 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 637581 + ... + 670190.

It is an arithmetic number, because the mean of its divisors is an integer number (2134283904).

Almost surely, 2^21323206155 is an apocalyptic number.

21323206155 is a deficient number, since it is larger than the sum of its proper divisors (12825336309).

21323206155 is a wasteful number, since it uses less digits than its factorization.

21323206155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1308866.

The product of its (nonzero) digits is 10800, while the sum is 30.

Adding to 21323206155 its reverse (55160232312), we get a palindrome (76483438467).

The spelling of 21323206155 in words is "twenty-one billion, three hundred twenty-three million, two hundred six thousand, one hundred fifty-five".