21155211352153 has 4 divisors (see below), whose sum is σ = 21155385838720. Its totient is φ = 21155036865588.

The previous prime is 21155211352141. The next prime is 21155211352199. The reversal of 21155211352153 is 35125311255112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21155211352153 - 2²¹ = 21155209255001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21155211352133) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 87061293 + ... + 87303946.

It is an arithmetic number, because the mean of its divisors is an integer number (5288846459680).

Almost surely, 2^{21155211352153} is an apocalyptic number.

It is an amenable number.

21155211352153 is a deficient number, since it is larger than the sum of its proper divisors (174486567).

21155211352153 is a wasteful number, since it uses less digits than its factorization.

21155211352153 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174486566.

The product of its digits is 45000, while the sum is 37.

The spelling of 21155211352153 in words is "twenty-one trillion, one hundred fifty-five billion, two hundred eleven million, three hundred fifty-two thousand, one hundred fifty-three".