21155360033155 has 12 divisors (see below), whose sum is σ = 26792882570592. Its totient is φ = 16033536023760.

The previous prime is 21155360033147. The next prime is 21155360033179. The reversal of 21155360033155 is 55133006355112.

It is not a de Polignac number, because 21155360033155 - 2³ = 21155360033147 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5860208731 + ... + 5860212340.

It is an arithmetic number, because the mean of its divisors is an integer number (2232740214216).

Almost surely, 2^{21155360033155} is an apocalyptic number.

21155360033155 is a deficient number, since it is larger than the sum of its proper divisors (5637522537437).

21155360033155 is a wasteful number, since it uses less digits than its factorization.

21155360033155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11720421114 (or 11720421095 counting only the distinct ones).

The product of its (nonzero) digits is 202500, while the sum is 40.

Adding to 21155360033155 its reverse (55133006355112), we get a palindrome (76288366388267).

The spelling of 21155360033155 in words is "twenty-one trillion, one hundred fifty-five billion, three hundred sixty million, thirty-three thousand, one hundred fifty-five".