646432518 has 16 divisors (see below), whose sum is σ = 1293295680. Its totient is φ = 215405736.

The previous prime is 646432489. The next prime is 646432519. The reversal of 646432518 is 815234646.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646432519) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3553 + ... + 36131.

It is an arithmetic number, because the mean of its divisors is an integer number (80830980).

Almost surely, 2^646432518 is an apocalyptic number.

646432518 is an abundant number, since it is smaller than the sum of its proper divisors (646863162).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

646432518 is a wasteful number, since it uses less digits than its factorization.

646432518 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35891.

The product of its digits is 138240, while the sum is 39.

The square root of 646432518 is about 25425.0372271114. The cubic root of 646432518 is about 864.6514318333.

It can be divided in two parts, 64643 and 2518, that added together give a triangular number (67161 = T₃₆₆).

The spelling of 646432518 in words is "six hundred forty-six million, four hundred thirty-two thousand, five hundred eighteen".