1640231 has 2 divisors, whose sum is σ = 1640232. Its totient is φ = 1640230.

The previous prime is 1640207. The next prime is 1640263. The reversal of 1640231 is 1320461.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1640231 - 2⁶ = 1640167 is a prime.

It is a super-2 number, since 2×1640231² = 5380715466722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1640201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 820115 + 820116.

It is an arithmetic number, because the mean of its divisors is an integer number (820116).

2^1640231 is an apocalyptic number.

1640231 is a deficient number, since it is larger than the sum of its proper divisors (1).

1640231 is an equidigital number, since it uses as much as digits as its factorization.

1640231 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 1640231 is about 1280.7150346584. The cubic root of 1640231 is about 117.9329073733.

Adding to 1640231 its reverse (1320461), we get a palindrome (2960692).

The spelling of 1640231 in words is "one million, six hundred forty thousand, two hundred thirty-one".