1640406663 has 54 divisors (see below), whose sum is σ = 2855298264. Its totient is φ = 904847328.

The previous prime is 1640406659. The next prime is 1640406671. The reversal of 1640406663 is 3666040461.

It is not a de Polignac number, because 1640406663 - 2² = 1640406659 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1640406623) by changing a digit.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 368670 + ... + 373092.

Almost surely, 2^1640406663 is an apocalyptic number.

1640406663 is a deficient number, since it is larger than the sum of its proper divisors (1214891601).

1640406663 is a wasteful number, since it uses less digits than its factorization.

1640406663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4501 (or 4462 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 36.

The square root of 1640406663 is about 40501.9340649308. The cubic root of 1640406663 is about 1179.3711729028.

The spelling of 1640406663 in words is "one billion, six hundred forty million, four hundred six thousand, six hundred sixty-three".