1690882561 has 4 divisors (see below), whose sum is σ = 1779876400. Its totient is φ = 1601888724.

The previous prime is 1690882547. The next prime is 1690882579. The reversal of 1690882561 is 1652880961.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1652880961 = 27823 ⋅59407.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1690882561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1690882541) 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 3 ways as a sum of consecutive naturals, for example, 44496891 + ... + 44496928.

It is an arithmetic number, because the mean of its divisors is an integer number (444969100).

Almost surely, 2^1690882561 is an apocalyptic number.

It is an amenable number.

1690882561 is a deficient number, since it is larger than the sum of its proper divisors (88993839).

1690882561 is an equidigital number, since it uses as much as digits as its factorization.

1690882561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88993838.

The product of its (nonzero) digits is 207360, while the sum is 46.

The square root of 1690882561 is about 41120.3424231851. The cubic root of 1690882561 is about 1191.3457367104.

The spelling of 1690882561 in words is "one billion, six hundred ninety million, eight hundred eighty-two thousand, five hundred sixty-one".