1661009219 has 2 divisors, whose sum is σ = 1661009220. Its totient is φ = 1661009218.

The previous prime is 1661009201. The next prime is 1661009263. The reversal of 1661009219 is 9129001661.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1661009219 is a prime.

It is a super-2 number, since 2×1661009219² = 5517903251205979922, which contains 22 as substring.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (1661009269) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 830504609 + 830504610.

It is an arithmetic number, because the mean of its divisors is an integer number (830504610).

Almost surely, 2^1661009219 is an apocalyptic number.

1661009219 is a deficient number, since it is larger than the sum of its proper divisors (1).

1661009219 is an equidigital number, since it uses as much as digits as its factorization.

1661009219 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5832, while the sum is 35.

The square root of 1661009219 is about 40755.4808461390. The cubic root of 1661009219 is about 1184.2880515197.

The spelling of 1661009219 in words is "one billion, six hundred sixty-one million, nine thousand, two hundred nineteen".