21440514430253 has 8 divisors (see below), whose sum is σ = 21508507723320. Its totient is φ = 21372523386880.

The previous prime is 21440514430249. The next prime is 21440514430289. The reversal of 21440514430253 is 35203441504412.

It can be written as a sum of positive squares in 4 ways, for example, as 673873526404 + 20766640903849 = 820898^2 + 4557043^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 21440514430253 - 2² = 21440514430249 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21440510430253) 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, 19681853 + ... + 20742621.

It is an arithmetic number, because the mean of its divisors is an integer number (2688563465415).

Almost surely, 2^{21440514430253} is an apocalyptic number.

It is an amenable number.

21440514430253 is a deficient number, since it is larger than the sum of its proper divisors (67993293067).

21440514430253 is a wasteful number, since it uses less digits than its factorization.

21440514430253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1124847.

The product of its (nonzero) digits is 230400, while the sum is 38.

Adding to 21440514430253 its reverse (35203441504412), we get a palindrome (56643955934665).

The spelling of 21440514430253 in words is "twenty-one trillion, four hundred forty billion, five hundred fourteen million, four hundred thirty thousand, two hundred fifty-three".