646591340 has 24 divisors (see below), whose sum is σ = 1363833072. Its totient is φ = 257495360.

The previous prime is 646591321. The next prime is 646591343. The reversal of 646591340 is 43195646.

It is a junction number, because it is equal to n+sod(n) for n = 646591294 and 646591303.

It is not an unprimeable number, because it can be changed into a prime (646591343) 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, 66671 + ... + 75750.

It is an arithmetic number, because the mean of its divisors is an integer number (56826378).

Almost surely, 2^646591340 is an apocalyptic number.

It is an amenable number.

646591340 is an abundant number, since it is smaller than the sum of its proper divisors (717241732).

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

646591340 is a wasteful number, since it uses less digits than its factorization.

646591340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142657 (or 142655 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 38.

The square root of 646591340 is about 25428.1603738847. The cubic root of 646591340 is about 864.7222381026.

The spelling of 646591340 in words is "six hundred forty-six million, five hundred ninety-one thousand, three hundred forty".