640365485 has 4 divisors (see below), whose sum is σ = 768438588. Its totient is φ = 512292384.

The previous prime is 640365461. The next prime is 640365497. The reversal of 640365485 is 584563046.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 584563046 = 2 ⋅292281523.

It can be written as a sum of positive squares in 2 ways, for example, as 486952489 + 153412996 = 22067^2 + 12386^2 .

It is a cyclic number.

It is not a de Polignac number, because 640365485 - 2¹⁶ = 640299949 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64036544 + ... + 64036553.

It is an arithmetic number, because the mean of its divisors is an integer number (192109647).

Almost surely, 2^640365485 is an apocalyptic number.

It is an amenable number.

640365485 is a deficient number, since it is larger than the sum of its proper divisors (128073103).

640365485 is a wasteful number, since it uses less digits than its factorization.

640365485 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128073102.

The product of its (nonzero) digits is 345600, while the sum is 41.

The square root of 640365485 is about 25305.4437819217. The cubic root of 640365485 is about 861.9378892879.

The spelling of 640365485 in words is "six hundred forty million, three hundred sixty-five thousand, four hundred eighty-five".