646513543 has 16 divisors (see below), whose sum is σ = 732525696. Its totient is φ = 566472960.

The previous prime is 646513537. The next prime is 646513547. The reversal of 646513543 is 345315646.

It is a de Polignac number, because none of the positive numbers 2^k-646513543 is a prime.

It is a super-2 number, since 2×646513543² = 835959522564825698, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646513547) 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, 3330 + ... + 36112.

It is an arithmetic number, because the mean of its divisors is an integer number (45782856).

Almost surely, 2^646513543 is an apocalyptic number.

646513543 is a deficient number, since it is larger than the sum of its proper divisors (86012153).

646513543 is a wasteful number, since it uses less digits than its factorization.

646513543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32874.

The product of its digits is 129600, while the sum is 37.

The square root of 646513543 is about 25426.6305868473. The cubic root of 646513543 is about 864.6875559728.

The spelling of 646513543 in words is "six hundred forty-six million, five hundred thirteen thousand, five hundred forty-three".