21455532240401 has 4 divisors (see below), whose sum is σ = 24520608274752. Its totient is φ = 18390456206052.

The previous prime is 21455532240397. The next prime is 21455532240419. The reversal of 21455532240401 is 10404223555412.

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 not a de Polignac number, because 21455532240401 - 2² = 21455532240397 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21455532240001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1532538017165 + ... + 1532538017178.

It is an arithmetic number, because the mean of its divisors is an integer number (6130152068688).

Almost surely, 2^{21455532240401} is an apocalyptic number.

It is an amenable number.

21455532240401 is a deficient number, since it is larger than the sum of its proper divisors (3065076034351).

21455532240401 is an equidigital number, since it uses as much as digits as its factorization.

21455532240401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3065076034350.

The product of its (nonzero) digits is 192000, while the sum is 38.

Adding to 21455532240401 its reverse (10404223555412), we get a palindrome (31859755795813).

The spelling of 21455532240401 in words is "twenty-one trillion, four hundred fifty-five billion, five hundred thirty-two million, two hundred forty thousand, four hundred one".