1645894647 has 16 divisors (see below), whose sum is σ = 2468468960. Its totient is φ = 1097261640.

The previous prime is 1645894639. The next prime is 1645894669. The reversal of 1645894647 is 7464985461.

1645894647 is a `hidden beast` number, since 16 + 4 + 589 + 4 + 6 + 47 = 666.

It is not a de Polignac number, because 1645894647 - 2³ = 1645894639 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1645894593 and 1645894602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1645896647) 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, 374104 + ... + 378477.

It is an arithmetic number, because the mean of its divisors is an integer number (154279310).

Almost surely, 2^1645894647 is an apocalyptic number.

1645894647 is a deficient number, since it is larger than the sum of its proper divisors (822574313).

1645894647 is an frugal number, since it uses more digits than its factorization.

1645894647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 752602 (or 752584 counting only the distinct ones).

The product of its digits is 5806080, while the sum is 54.

The square root of 1645894647 is about 40569.6271488906. The cubic root of 1645894647 is about 1180.6849052192.

The spelling of 1645894647 in words is "one billion, six hundred forty-five million, eight hundred ninety-four thousand, six hundred forty-seven".