21154533141601 has 8 divisors (see below), whose sum is σ = 21159605026664. Its totient is φ = 21149461584000.

The previous prime is 21154533141593. The next prime is 21154533141617. The reversal of 21154533141601 is 10614133545112.

It can be written as a sum of positive squares in 4 ways, for example, as 2079433216576 + 19075099925025 = 1442024^2 + 4367505^2 .

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 21154533141601 - 2³ = 21154533141593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21154533141671) 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, 170131285 + ... + 170255581.

It is an arithmetic number, because the mean of its divisors is an integer number (2644950628333).

Almost surely, 2^{21154533141601} is an apocalyptic number.

It is an amenable number.

21154533141601 is a deficient number, since it is larger than the sum of its proper divisors (5071885063).

21154533141601 is a wasteful number, since it uses less digits than its factorization.

21154533141601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163731.

The product of its (nonzero) digits is 43200, while the sum is 37.

Adding to 21154533141601 its reverse (10614133545112), we get a palindrome (31768666686713).

The spelling of 21154533141601 in words is "twenty-one trillion, one hundred fifty-four billion, five hundred thirty-three million, one hundred forty-one thousand, six hundred one".