21605266777696 has 48 divisors (see below), whose sum is σ = 48994620788736. Its totient is φ = 9186491373696.

The previous prime is 21605266777649. The next prime is 21605266777769. The reversal of 21605266777696 is 69677766250612.

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 7 ways as a sum of consecutive naturals, for example, 379704166 + ... + 379761061.

It is an arithmetic number, because the mean of its divisors is an integer number (1020721266432).

Almost surely, 2^{21605266777696} is an apocalyptic number.

It is an amenable number.

21605266777696 is an abundant number, since it is smaller than the sum of its proper divisors (27389354011040).

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

21605266777696 is a wasteful number, since it uses less digits than its factorization.

21605266777696 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 759465371 (or 759465363 counting only the distinct ones).

The product of its (nonzero) digits is 480090240, while the sum is 70.

The spelling of 21605266777696 in words is "twenty-one trillion, six hundred five billion, two hundred sixty-six million, seven hundred seventy-seven thousand, six hundred ninety-six".