1661430215 has 4 divisors (see below), whose sum is σ = 1993716264. Its totient is φ = 1329144168.

The previous prime is 1661430209. The next prime is 1661430227. The reversal of 1661430215 is 5120341661.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1661430215 - 2¹⁰ = 1661429191 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 166143017 + ... + 166143026.

It is an arithmetic number, because the mean of its divisors is an integer number (498429066).

Almost surely, 2^1661430215 is an apocalyptic number.

1661430215 is a deficient number, since it is larger than the sum of its proper divisors (332286049).

1661430215 is an equidigital number, since it uses as much as digits as its factorization.

1661430215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332286048.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 1661430215 is about 40760.6454193257. The cubic root of 1661430215 is about 1184.3880988102.

Adding to 1661430215 its reverse (5120341661), we get a palindrome (6781771876).

The spelling of 1661430215 in words is "one billion, six hundred sixty-one million, four hundred thirty thousand, two hundred fifteen".