221805021869 has 16 divisors (see below), whose sum is σ = 232868259072. Its totient is φ = 210860947968.

The previous prime is 221805021853. The next prime is 221805021871. The reversal of 221805021869 is 968120508122.

It is a cyclic number.

It is not a de Polignac number, because 221805021869 - 2⁴ = 221805021853 is a prime.

It is a super-2 number, since 2×221805021869² (a number of 23 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 (221805021469) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13771229 + ... + 13787325.

It is an arithmetic number, because the mean of its divisors is an integer number (14554266192).

Almost surely, 2^221805021869 is an apocalyptic number.

It is an amenable number.

221805021869 is a deficient number, since it is larger than the sum of its proper divisors (11063237203).

221805021869 is a wasteful number, since it uses less digits than its factorization.

221805021869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19756.

The product of its (nonzero) digits is 138240, while the sum is 44.

The spelling of 221805021869 in words is "two hundred twenty-one billion, eight hundred five million, twenty-one thousand, eight hundred sixty-nine".