21354617106405 has 96 divisors (see below), whose sum is σ = 40967021047680. Its totient is φ = 10204230666240.

The previous prime is 21354617106401. The next prime is 21354617106461. The reversal of 21354617106405 is 50460171645312.

It is a happy number.

21354617106405 is a `hidden beast` number, since 2 + 1 + 35 + 46 + 171 + 0 + 6 + 405 = 666.

It is not a de Polignac number, because 21354617106405 - 2² = 21354617106401 is a prime.

It is a super-2 number, since 2×21354617106405² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21354617106401) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 8293569 + ... + 10559001.

It is an arithmetic number, because the mean of its divisors is an integer number (426739802580).

Almost surely, 2^{21354617106405} is an apocalyptic number.

It is an amenable number.

21354617106405 is a deficient number, since it is larger than the sum of its proper divisors (19612403941275).

21354617106405 is a wasteful number, since it uses less digits than its factorization.

21354617106405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2265731 (or 2265728 counting only the distinct ones).

The product of its (nonzero) digits is 604800, while the sum is 45.

The spelling of 21354617106405 in words is "twenty-one trillion, three hundred fifty-four billion, six hundred seventeen million, one hundred six thousand, four hundred five".