1640322431 has 8 divisors (see below), whose sum is σ = 1789766400. Its totient is φ = 1490932440.

The previous prime is 1640322413. The next prime is 1640322433. The reversal of 1640322431 is 1342230461.

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

It is a cyclic number.

It is not a de Polignac number, because 1640322431 - 2²⁶ = 1573213567 is a prime.

It is a super-2 number, since 2×1640322431² = 5381315355283499522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1640322431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1640322433) 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, 75740 + ... + 94958.

It is an arithmetic number, because the mean of its divisors is an integer number (223720800).

Almost surely, 2^1640322431 is an apocalyptic number.

1640322431 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1640322431 is a deficient number, since it is larger than the sum of its proper divisors (149443969).

1640322431 is a wasteful number, since it uses less digits than its factorization.

1640322431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26989.

The product of its (nonzero) digits is 3456, while the sum is 26.

The square root of 1640322431 is about 40500.8942000050. The cubic root of 1640322431 is about 1179.3509863447.

Adding to 1640322431 its reverse (1342230461), we get a palindrome (2982552892).

The spelling of 1640322431 in words is "one billion, six hundred forty million, three hundred twenty-two thousand, four hundred thirty-one".