1644974513 has 24 divisors (see below), whose sum is σ = 2124252288. Its totient is φ = 1244909952.

The previous prime is 1644974497. The next prime is 1644974567. The reversal of 1644974513 is 3154794461.

It is not a de Polignac number, because 1644974513 - 2⁴ = 1644974497 is a prime.

It is a super-2 number, since 2×1644974513² = 5411882296839174338, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1644979513) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3020 + ... + 57437.

It is an arithmetic number, because the mean of its divisors is an integer number (88510512).

Almost surely, 2^1644974513 is an apocalyptic number.

1644974513 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

1644974513 is a deficient number, since it is larger than the sum of its proper divisors (479277775).

1644974513 is a wasteful number, since it uses less digits than its factorization.

1644974513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60513 (or 60500 counting only the distinct ones).

The product of its digits is 362880, while the sum is 44.

The square root of 1644974513 is about 40558.2853804250. The cubic root of 1644974513 is about 1180.4648443875.

The spelling of 1644974513 in words is "one billion, six hundred forty-four million, nine hundred seventy-four thousand, five hundred thirteen".