21144325501 has 8 divisors (see below), whose sum is σ = 24110271864. Its totient is φ = 18369730560.

The previous prime is 21144325493. The next prime is 21144325577. The reversal of 21144325501 is 10552344112.

It can be written as a sum of positive squares in 4 ways, for example, as 10725625 + 21133599876 = 3275^2 + 145374^2 .

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 21144325501 - 2³ = 21144325493 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21144325501.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21144325001) 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, 47837620 + ... + 47838061.

It is an arithmetic number, because the mean of its divisors is an integer number (3013783983).

Almost surely, 2^21144325501 is an apocalyptic number.

It is an amenable number.

21144325501 is a deficient number, since it is larger than the sum of its proper divisors (2965946363).

21144325501 is a wasteful number, since it uses less digits than its factorization.

21144325501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95675711.

The product of its (nonzero) digits is 4800, while the sum is 28.

Adding to 21144325501 its reverse (10552344112), we get a palindrome (31696669613).

The spelling of 21144325501 in words is "twenty-one billion, one hundred forty-four million, three hundred twenty-five thousand, five hundred one".