1661670697 has 2 divisors, whose sum is σ = 1661670698. Its totient is φ = 1661670696.

The previous prime is 1661670677. The next prime is 1661670721. The reversal of 1661670697 is 7960761661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1455346201 + 206324496 = 38149^2 + 14364^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1661670697 is a prime.

It is a super-2 number, since 2×1661670697² = 5522299010536931618, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1661670697.

It is not a weakly prime, because it can be changed into another prime (1661670607) 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 as a sum of consecutive naturals, namely, 830835348 + 830835349.

It is an arithmetic number, because the mean of its divisors is an integer number (830835349).

Almost surely, 2^1661670697 is an apocalyptic number.

It is an amenable number.

1661670697 is a deficient number, since it is larger than the sum of its proper divisors (1).

1661670697 is an equidigital number, since it uses as much as digits as its factorization.

1661670697 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 571536, while the sum is 49.

The square root of 1661670697 is about 40763.5952413425. The cubic root of 1661670697 is about 1184.4452403972.

The spelling of 1661670697 in words is "one billion, six hundred sixty-one million, six hundred seventy thousand, six hundred ninety-seven".