21365414155 has 4 divisors (see below), whose sum is σ = 25638496992. Its totient is φ = 17092331320.

The previous prime is 21365414153. The next prime is 21365414167. The reversal of 21365414155 is 55141456312.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21365414155 - 2¹ = 21365414153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21365414153) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2136541411 + ... + 2136541420.

It is an arithmetic number, because the mean of its divisors is an integer number (6409624248).

Almost surely, 2^21365414155 is an apocalyptic number.

21365414155 is a deficient number, since it is larger than the sum of its proper divisors (4273082837).

21365414155 is an equidigital number, since it uses as much as digits as its factorization.

21365414155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4273082836.

The product of its digits is 72000, while the sum is 37.

The spelling of 21365414155 in words is "twenty-one billion, three hundred sixty-five million, four hundred fourteen thousand, one hundred fifty-five".