21641356037647 has 8 divisors (see below), whose sum is σ = 23533684467696. Its totient is φ = 19817839550592.

The previous prime is 21641356037633. The next prime is 21641356037657. The reversal of 21641356037647 is 74673065314612.

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 21641356037647 - 2¹⁹ = 21641355513359 is a prime.

It is a super-2 number, since 2×21641356037647² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21641356037657) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17202985093 + ... + 17202986350.

It is an arithmetic number, because the mean of its divisors is an integer number (2941710558462).

Almost surely, 2^{21641356037647} is an apocalyptic number.

21641356037647 is a deficient number, since it is larger than the sum of its proper divisors (1892328430049).

21641356037647 is a wasteful number, since it uses less digits than its factorization.

21641356037647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34405971497.

The product of its (nonzero) digits is 15240960, while the sum is 55.

The spelling of 21641356037647 in words is "twenty-one trillion, six hundred forty-one billion, three hundred fifty-six million, thirty-seven thousand, six hundred forty-seven".