640894461 has 8 divisors (see below), whose sum is σ = 883992480. Its totient is φ = 412529712.

The previous prime is 640894459. The next prime is 640894469. The reversal of 640894461 is 164498046.

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

It is not a de Polignac number, because 640894461 - 2¹ = 640894459 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640894469) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3683215 + ... + 3683388.

It is an arithmetic number, because the mean of its divisors is an integer number (110499060).

Almost surely, 2^640894461 is an apocalyptic number.

It is an amenable number.

640894461 is a deficient number, since it is larger than the sum of its proper divisors (243098019).

640894461 is a wasteful number, since it uses less digits than its factorization.

640894461 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7366635.

The product of its (nonzero) digits is 165888, while the sum is 42.

The square root of 640894461 is about 25315.8934466078. The cubic root of 640894461 is about 862.1751595033.

The spelling of 640894461 in words is "six hundred forty million, eight hundred ninety-four thousand, four hundred sixty-one".