21778205404461 has 32 divisors (see below), whose sum is σ = 32425651399680. Its totient is φ = 12887355936000.

The previous prime is 21778205404451. The next prime is 21778205404589. The reversal of 21778205404461 is 16440450287712.

It is not a de Polignac number, because 21778205404461 - 2²³ = 21778197015853 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21778205404451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1234960 + ... + 6714278.

It is an arithmetic number, because the mean of its divisors is an integer number (1013301606240).

Almost surely, 2^{21778205404461} is an apocalyptic number.

It is an amenable number.

21778205404461 is a deficient number, since it is larger than the sum of its proper divisors (10647445995219).

21778205404461 is a wasteful number, since it uses less digits than its factorization.

21778205404461 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5482177.

The product of its (nonzero) digits is 3010560, while the sum is 51.

The spelling of 21778205404461 in words is "twenty-one trillion, seven hundred seventy-eight billion, two hundred five million, four hundred four thousand, four hundred sixty-one".