1640798 has 4 divisors (see below), whose sum is σ = 2461200. Its totient is φ = 820398.

The previous prime is 1640773. The next prime is 1640803. The reversal of 1640798 is 8970461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8970461 = 433 ⋅20717.

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410198 + ... + 410201.

It is an arithmetic number, because the mean of its divisors is an integer number (615300).

2^1640798 is an apocalyptic number.

1640798 is a deficient number, since it is larger than the sum of its proper divisors (820402).

1640798 is an equidigital number, since it uses as much as digits as its factorization.

1640798 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 820401.

The product of its (nonzero) digits is 12096, while the sum is 35.

The square root of 1640798 is about 1280.9363762498. The cubic root of 1640798 is about 117.9464949422.

The spelling of 1640798 in words is "one million, six hundred forty thousand, seven hundred ninety-eight".