1640257585 has 16 divisors (see below), whose sum is σ = 2034385920. Its totient is φ = 1268262720.

The previous prime is 1640257579. The next prime is 1640257589. The reversal of 1640257585 is 5857520461.

It is not a de Polignac number, because 1640257585 - 2⁷ = 1640257457 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1640257589) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 123739 + ... + 136351.

It is an arithmetic number, because the mean of its divisors is an integer number (127149120).

Almost surely, 2^1640257585 is an apocalyptic number.

It is an amenable number.

1640257585 is a deficient number, since it is larger than the sum of its proper divisors (394128335).

1640257585 is a wasteful number, since it uses less digits than its factorization.

1640257585 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13488.

The product of its (nonzero) digits is 336000, while the sum is 43.

The square root of 1640257585 is about 40500.0936418671. The cubic root of 1640257585 is about 1179.3354452534.

The spelling of 1640257585 in words is "one billion, six hundred forty million, two hundred fifty-seven thousand, five hundred eighty-five".