640063349 has 8 divisors (see below), whose sum is σ = 643719960. Its totient is φ = 636414976.

The previous prime is 640063339. The next prime is 640063357. The reversal of 640063349 is 943360046.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 42016324 + 598047025 = 6482^2 + 24455^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-640063349 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640063339) 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, 214979 + ... + 217935.

It is an arithmetic number, because the mean of its divisors is an integer number (80464995).

Almost surely, 2^640063349 is an apocalyptic number.

It is an amenable number.

640063349 is a deficient number, since it is larger than the sum of its proper divisors (3656611).

640063349 is a wasteful number, since it uses less digits than its factorization.

640063349 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4119.

The product of its (nonzero) digits is 46656, while the sum is 35.

The square root of 640063349 is about 25299.4732949127. The cubic root of 640063349 is about 861.8023086753.

The spelling of 640063349 in words is "six hundred forty million, sixty-three thousand, three hundred forty-nine".