21493477845 has 192 divisors, whose sum is σ = 46169671680. Its totient is φ = 9449395200.

The previous prime is 21493477823. The next prime is 21493477849. The reversal of 21493477845 is 54877439412.

21493477845 is a `hidden beast` number, since 2 + 1 + 4 + 93 + 477 + 84 + 5 = 666.

It is not a de Polignac number, because 21493477845 - 2⁵ = 21493477813 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21493477791 and 21493477800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21493477849) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 57623079 + ... + 57623451.

It is an arithmetic number, because the mean of its divisors is an integer number (240467040).

Almost surely, 2^21493477845 is an apocalyptic number.

It is an amenable number.

21493477845 is an abundant number, since it is smaller than the sum of its proper divisors (24676193835).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21493477845 is a wasteful number, since it uses less digits than its factorization.

21493477845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 713 (or 700 counting only the distinct ones).

The product of its digits is 6773760, while the sum is 54.

The spelling of 21493477845 in words is "twenty-one billion, four hundred ninety-three million, four hundred seventy-seven thousand, eight hundred forty-five".