1640247 has 16 divisors (see below), whose sum is σ = 2568192. Its totient is φ = 911520.

The previous prime is 1640231. The next prime is 1640263. The reversal of 1640247 is 7420461.

It is an interprime number because it is at equal distance from previous prime (1640231) and next prime (1640263).

It is not a de Polignac number, because 1640247 - 2⁴ = 1640231 is a prime.

It is a plaindrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1640207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 279 + ... + 1832.

It is an arithmetic number, because the mean of its divisors is an integer number (160512).

2^1640247 is an apocalyptic number.

1640247 is a deficient number, since it is larger than the sum of its proper divisors (927945).

1640247 is a wasteful number, since it uses less digits than its factorization.

1640247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2158.

The product of its (nonzero) digits is 1344, while the sum is 24.

The square root of 1640247 is about 1280.7212811537. The cubic root of 1640247 is about 117.9332908397.

The spelling of 1640247 in words is "one million, six hundred forty thousand, two hundred forty-seven".