21377647267447 has 32 divisors (see below), whose sum is σ = 23160924864000. Its totient is φ = 19657227110400.

The previous prime is 21377647267421. The next prime is 21377647267463. The reversal of 21377647267447 is 74476274677312.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21377647267447 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 (21377647264447) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 175784172 + ... + 175905742.

It is an arithmetic number, because the mean of its divisors is an integer number (723778902000).

Almost surely, 2^{21377647267447} is an apocalyptic number.

21377647267447 is a deficient number, since it is larger than the sum of its proper divisors (1783277596553).

21377647267447 is a wasteful number, since it uses less digits than its factorization.

21377647267447 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122727.

The product of its digits is 464679936, while the sum is 67.

The spelling of 21377647267447 in words is "twenty-one trillion, three hundred seventy-seven billion, six hundred forty-seven million, two hundred sixty-seven thousand, four hundred forty-seven".