1640338406 has 12 divisors (see below), whose sum is σ = 2862223308. Its totient is φ = 703002132.

The previous prime is 1640338387. The next prime is 1640338409. The reversal of 1640338406 is 6048330461.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1640338409) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8368976 + ... + 8369171.

It is an arithmetic number, because the mean of its divisors is an integer number (238518609).

Almost surely, 2^1640338406 is an apocalyptic number.

1640338406 is a deficient number, since it is larger than the sum of its proper divisors (1221884902).

1640338406 is a wasteful number, since it uses less digits than its factorization.

1640338406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16738163 (or 16738156 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 35.

The square root of 1640338406 is about 40501.0914173927. The cubic root of 1640338406 is about 1179.3548148747.

Adding to 1640338406 its reverse (6048330461), we get a palindrome (7688668867).

The spelling of 1640338406 in words is "one billion, six hundred forty million, three hundred thirty-eight thousand, four hundred six".