1690664509 has 8 divisors (see below), whose sum is σ = 1696896000. Its totient is φ = 1684445232.

The previous prime is 1690664461. The next prime is 1690664527. The reversal of 1690664509 is 9054660961.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1690664509 is a prime.

It is a super-4 number, since 4×1690664509⁴ (a number of 38 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1690664809) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 341947 + ... + 346855.

It is an arithmetic number, because the mean of its divisors is an integer number (212112000).

Almost surely, 2^1690664509 is an apocalyptic number.

It is an amenable number.

1690664509 is a deficient number, since it is larger than the sum of its proper divisors (6231491).

1690664509 is an equidigital number, since it uses as much as digits as its factorization.

1690664509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6107.

The product of its (nonzero) digits is 349920, while the sum is 46.

The square root of 1690664509 is about 41117.6909492739. The cubic root of 1690664509 is about 1191.2945235168.

The spelling of 1690664509 in words is "one billion, six hundred ninety million, six hundred sixty-four thousand, five hundred nine".