1690749 has 6 divisors (see below), whose sum is σ = 2442206. Its totient is φ = 1127160.

The previous prime is 1690739. The next prime is 1690757. The reversal of 1690749 is 9470961.

It can be written as a sum of positive squares in only one way, i.e., 980100 + 710649 = 990^2 + 843^2 .

It is not a de Polignac number, because 1690749 - 2⁷ = 1690621 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1690739) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 93922 + ... + 93939.

2^1690749 is an apocalyptic number.

It is an amenable number.

1690749 is a deficient number, since it is larger than the sum of its proper divisors (751457).

1690749 is a wasteful number, since it uses less digits than its factorization.

1690749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 187867 (or 187864 counting only the distinct ones).

The product of its (nonzero) digits is 13608, while the sum is 36.

The square root of 1690749 is about 1300.2880450116. The cubic root of 1690749 is about 119.1314368177.

The spelling of 1690749 in words is "one million, six hundred ninety thousand, seven hundred forty-nine".