444163781 has 2 divisors, whose sum is σ = 444163782. Its totient is φ = 444163780.

The previous prime is 444163747. The next prime is 444163801. The reversal of 444163781 is 187361444.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 439279681 + 4884100 = 20959^2 + 2210^2 .

It is a cyclic number.

It is not a de Polignac number, because 444163781 - 2¹⁴ = 444147397 is a prime.

It is a super-2 number, since 2×444163781² = 394562928704431922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (444163081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 222081890 + 222081891.

It is an arithmetic number, because the mean of its divisors is an integer number (222081891).

Almost surely, 2^444163781 is an apocalyptic number.

It is an amenable number.

444163781 is a deficient number, since it is larger than the sum of its proper divisors (1).

444163781 is an equidigital number, since it uses as much as digits as its factorization.

444163781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 64512, while the sum is 38.

The square root of 444163781 is about 21075.1934985186. The cubic root of 444163781 is about 762.9821548216.

The spelling of 444163781 in words is "four hundred forty-four million, one hundred sixty-three thousand, seven hundred eighty-one".