1645444997000 has 128 divisors (see below), whose sum is σ = 4406407050240. Its totient is φ = 563381164800.

The previous prime is 1645444996999. The next prime is 1645444997023. The reversal of 1645444997000 is 7994445461.

It is a Cunningham number, because it is equal to 1282749²-1.

It is a hoax number, since the sum of its digits (53) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4970657 + ... + 5291343.

It is an arithmetic number, because the mean of its divisors is an integer number (34425055080).

Almost surely, 2^{1645444997000} is an apocalyptic number.

1645444997000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1645444997000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2203203525120).

1645444997000 is an abundant number, since it is smaller than the sum of its proper divisors (2760962053240).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1645444997000 is a wasteful number, since it uses less digits than its factorization.

1645444997000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321448 (or 321434 counting only the distinct ones).

The product of its (nonzero) digits is 4354560, while the sum is 53.

The spelling of 1645444997000 in words is "one trillion, six hundred forty-five billion, four hundred forty-four million, nine hundred ninety-seven thousand".