646400523 has 8 divisors (see below), whose sum is σ = 874731328. Its totient is φ = 424501704.

The previous prime is 646400507. The next prime is 646400563. The reversal of 646400523 is 325004646.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 646400523 - 2⁴ = 646400507 is a prime.

It is a super-3 number, since 3×646400523³ (a number of 27 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (646400563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1607761 + ... + 1608162.

It is an arithmetic number, because the mean of its divisors is an integer number (109341416).

Almost surely, 2^646400523 is an apocalyptic number.

646400523 is a deficient number, since it is larger than the sum of its proper divisors (228330805).

646400523 is a wasteful number, since it uses less digits than its factorization.

646400523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3215993.

The product of its (nonzero) digits is 17280, while the sum is 30.

The square root of 646400523 is about 25424.4080167071. The cubic root of 646400523 is about 864.6371663696.

The spelling of 646400523 in words is "six hundred forty-six million, four hundred thousand, five hundred twenty-three".