1645613444 has 48 divisors (see below), whose sum is σ = 2999420928. Its totient is φ = 789494688.

The previous prime is 1645613423. The next prime is 1645613467. The reversal of 1645613444 is 4443165461.

It is a super-2 number, since 2×1645613444² = 5416087214147082272, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1645613398 and 1645613407.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2543129 + ... + 2543775.

It is an arithmetic number, because the mean of its divisors is an integer number (62487936).

Almost surely, 2^1645613444 is an apocalyptic number.

It is an amenable number.

1645613444 is a deficient number, since it is larger than the sum of its proper divisors (1353807484).

1645613444 is a wasteful number, since it uses less digits than its factorization.

1645613444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 944 (or 942 counting only the distinct ones).

The product of its digits is 138240, while the sum is 38.

The square root of 1645613444 is about 40566.1613170386. The cubic root of 1645613444 is about 1180.6176609299.

The spelling of 1645613444 in words is "one billion, six hundred forty-five million, six hundred thirteen thousand, four hundred forty-four".