1640040427 has 8 divisors (see below), whose sum is σ = 1677931200. Its totient is φ = 1602407040.

The previous prime is 1640040403. The next prime is 1640040433. The reversal of 1640040427 is 7240400461.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1640040427 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1640040395 and 1640040404.

It is not an unprimeable number, because it can be changed into a prime (1640040497) 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, 51427 + ... + 76972.

It is an arithmetic number, because the mean of its divisors is an integer number (209741400).

Almost surely, 2^1640040427 is an apocalyptic number.

1640040427 is a deficient number, since it is larger than the sum of its proper divisors (37890773).

1640040427 is a wasteful number, since it uses less digits than its factorization.

1640040427 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128693.

The product of its (nonzero) digits is 5376, while the sum is 28.

The square root of 1640040427 is about 40497.4125963623. The cubic root of 1640040427 is about 1179.2833978531.

Adding to 1640040427 its reverse (7240400461), we get a palindrome (8880440888).

The spelling of 1640040427 in words is "one billion, six hundred forty million, forty thousand, four hundred twenty-seven".