1690640 has 40 divisors (see below), whose sum is σ = 4493760. Its totient is φ = 579456.

The previous prime is 1690621. The next prime is 1690651. The reversal of 1690640 is 460961.

It is a tau number, because it is divible by the number of its divisors (40).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 950 + ... + 2069.

It is an arithmetic number, because the mean of its divisors is an integer number (112344).

2^1690640 is an apocalyptic number.

1690640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1690640 is an abundant number, since it is smaller than the sum of its proper divisors (2803120).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1690640 is a wasteful number, since it uses less digits than its factorization.

1690640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3039 (or 3033 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 1690640 is about 1300.2461305461. The cubic root of 1690640 is about 119.1288766889.

It can be divided in two parts, 1690 and 640, that multiplied together give a square (1081600 = 1040²).

The spelling of 1690640 in words is "one million, six hundred ninety thousand, six hundred forty".