21647771450677 has 8 divisors (see below), whose sum is σ = 21745000551680. Its totient is φ = 21550543724160.

The previous prime is 21647771450639. The next prime is 21647771450681. The reversal of 21647771450677 is 77605417774612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21647771450677 - 2¹⁹ = 21647770926389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21647771450377) 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 7 ways as a sum of consecutive naturals, for example, 44101477 + ... + 44589637.

It is an arithmetic number, because the mean of its divisors is an integer number (2718125068960).

Almost surely, 2^{21647771450677} is an apocalyptic number.

It is an amenable number.

21647771450677 is a deficient number, since it is larger than the sum of its proper divisors (97229101003).

21647771450677 is a wasteful number, since it uses less digits than its factorization.

21647771450677 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 687243.

The product of its (nonzero) digits is 96808320, while the sum is 64.

The spelling of 21647771450677 in words is "twenty-one trillion, six hundred forty-seven billion, seven hundred seventy-one million, four hundred fifty thousand, six hundred seventy-seven".