1640736040 has 32 divisors (see below), whose sum is σ = 3712068360. Its totient is φ = 652665600.

The previous prime is 1640736037. The next prime is 1640736043. The reversal of 1640736040 is 406370461.

It is an interprime number because it is at equal distance from previous prime (1640736037) and next prime (1640736043).

It can be written as a sum of positive squares in 4 ways, for example, as 590587204 + 1050148836 = 24302^2 + 32406^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1640735993 and 1640736011.

It is not an unprimeable number, because it can be changed into a prime (1640736043) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 106071 + ... + 120550.

Almost surely, 2^1640736040 is an apocalyptic number.

1640736040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1640736040 is an abundant number, since it is smaller than the sum of its proper divisors (2071332320).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1640736040 is a wasteful number, since it uses less digits than its factorization.

1640736040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 226813 (or 226809 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 31.

The square root of 1640736040 is about 40506.0000493754. Note that the first 4 decimals coincide. The cubic root of 1640736040 is about 1179.4501028720.

The spelling of 1640736040 in words is "one billion, six hundred forty million, seven hundred thirty-six thousand, forty".