21738609045 has 96 divisors (see below), whose sum is σ = 40145414400. Its totient is φ = 10858890240.

The previous prime is 21738609029. The next prime is 21738609089. The reversal of 21738609045 is 54090683712.

21738609045 is a `hidden beast` number, since 2 + 1 + 7 + 38 + 609 + 0 + 4 + 5 = 666.

It is not a de Polignac number, because 21738609045 - 2⁴ = 21738609029 is a prime.

It is a super-2 number, since 2×21738609045² (a number of 21 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 an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 11256730 + ... + 11258660.

It is an arithmetic number, because the mean of its divisors is an integer number (418181400).

It is a 1-persistent number, because it is pandigital, but 2⋅21738609045 = 43477218090 is not.

Almost surely, 2^21738609045 is an apocalyptic number.

It is an amenable number.

21738609045 is a deficient number, since it is larger than the sum of its proper divisors (18406805355).

21738609045 is a wasteful number, since it uses less digits than its factorization.

21738609045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2187 (or 2184 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 45.

The spelling of 21738609045 in words is "twenty-one billion, seven hundred thirty-eight million, six hundred nine thousand, forty-five".