21205215144051 has 8 divisors (see below), whose sum is σ = 28321786497984. Its totient is φ = 14112726943080.

The previous prime is 21205215144013. The next prime is 21205215144097. The reversal of 21205215144051 is 15044151250212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21205215144051 - 2²³ = 21205206755443 is a prime.

It is a super-2 number, since 2×21205215144051² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21205215144011) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6020786185 + ... + 6020789706.

It is an arithmetic number, because the mean of its divisors is an integer number (3540223312248).

Almost surely, 2^{21205215144051} is an apocalyptic number.

21205215144051 is a deficient number, since it is larger than the sum of its proper divisors (7116571353933).

21205215144051 is a wasteful number, since it uses less digits than its factorization.

21205215144051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12041576481.

The product of its (nonzero) digits is 16000, while the sum is 33.

Adding to 21205215144051 its reverse (15044151250212), we get a palindrome (36249366394263).

The spelling of 21205215144051 in words is "twenty-one trillion, two hundred five billion, two hundred fifteen million, one hundred forty-four thousand, fifty-one".