21777828281623 has 16 divisors (see below), whose sum is σ = 22811742455040. Its totient is φ = 20751314500224.

The previous prime is 21777828281617. The next prime is 21777828281681. The reversal of 21777828281623 is 32618282877712.

It is a cyclic number.

It is not a de Polignac number, because 21777828281623 - 2⁴¹ = 19578805026071 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 (21777828251623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4903840 + ... + 8222122.

It is an arithmetic number, because the mean of its divisors is an integer number (1425733903440).

Almost surely, 2^{21777828281623} is an apocalyptic number.

21777828281623 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21777828281623 is a deficient number, since it is larger than the sum of its proper divisors (1033914173417).

21777828281623 is a wasteful number, since it uses less digits than its factorization.

21777828281623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3319398.

The product of its digits is 50577408, while the sum is 64.

The spelling of 21777828281623 in words is "twenty-one trillion, seven hundred seventy-seven billion, eight hundred twenty-eight million, two hundred eighty-one thousand, six hundred twenty-three".