1444147991 has 64 divisors (see below), whose sum is σ = 1873428480. Its totient is φ = 1093357440.

The previous prime is 1444147987. The next prime is 1444147993. The reversal of 1444147991 is 1997414441.

It is a cyclic number.

It is not a de Polignac number, because 1444147991 - 2² = 1444147987 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1444147993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 5490926 + ... + 5491188.

It is an arithmetic number, because the mean of its divisors is an integer number (29272320).

Almost surely, 2^1444147991 is an apocalyptic number.

1444147991 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1444147991 is a deficient number, since it is larger than the sum of its proper divisors (429280489).

1444147991 is a wasteful number, since it uses less digits than its factorization.

1444147991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 396.

The product of its digits is 145152, while the sum is 44.

The square root of 1444147991 is about 38001.9472001107. The cubic root of 1444147991 is about 1130.3264754843.

The spelling of 1444147991 in words is "one billion, four hundred forty-four million, one hundred forty-seven thousand, nine hundred ninety-one".