1644907097 has 4 divisors (see below), whose sum is σ = 1741666356. Its totient is φ = 1548147840.

The previous prime is 1644907091. The next prime is 1644907127. The reversal of 1644907097 is 7907094461.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7907094461 = 7 ⋅1129584923.

It can be written as a sum of positive squares in 2 ways, for example, as 1465052176 + 179854921 = 38276^2 + 13411^2 .

It is not a de Polignac number, because 1644907097 - 2²⁰ = 1643858521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1644907091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 48379604 + ... + 48379637.

It is an arithmetic number, because the mean of its divisors is an integer number (435416589).

Almost surely, 2^1644907097 is an apocalyptic number.

1644907097 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

1644907097 is a deficient number, since it is larger than the sum of its proper divisors (96759259).

1644907097 is an equidigital number, since it uses as much as digits as its factorization.

1644907097 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96759258.

The product of its (nonzero) digits is 381024, while the sum is 47.

The square root of 1644907097 is about 40557.4542716872. The cubic root of 1644907097 is about 1180.4487178346.

The spelling of 1644907097 in words is "one billion, six hundred forty-four million, nine hundred seven thousand, ninety-seven".