21305460554501 has 4 divisors (see below), whose sum is σ = 21305479497900. Its totient is φ = 21305441611104.

The previous prime is 21305460554467. The next prime is 21305460554509. The reversal of 21305460554501 is 10545506450312.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5347425002500 + 15958035552001 = 2312450^2 + 3994751^2 .

It is a cyclic number.

It is not a de Polignac number, because 21305460554501 - 2²² = 21305456360197 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 (21305460554509) 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, 7670486 + ... + 10072103.

It is an arithmetic number, because the mean of its divisors is an integer number (5326369874475).

Almost surely, 2^{21305460554501} is an apocalyptic number.

It is an amenable number.

21305460554501 is a deficient number, since it is larger than the sum of its proper divisors (18943399).

21305460554501 is a wasteful number, since it uses less digits than its factorization.

21305460554501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18943398.

The product of its (nonzero) digits is 360000, while the sum is 41.

The spelling of 21305460554501 in words is "twenty-one trillion, three hundred five billion, four hundred sixty million, five hundred fifty-four thousand, five hundred one".