1661213303 has 2 divisors, whose sum is σ = 1661213304. Its totient is φ = 1661213302.

The previous prime is 1661213287. The next prime is 1661213311. The reversal of 1661213303 is 3033121661.

It is a strong prime.

It is an emirp because it is prime and its reverse (3033121661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1661213303 - 2⁴ = 1661213287 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1661213903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 830606651 + 830606652.

It is an arithmetic number, because the mean of its divisors is an integer number (830606652).

Almost surely, 2^1661213303 is an apocalyptic number.

1661213303 is a deficient number, since it is larger than the sum of its proper divisors (1).

1661213303 is an equidigital number, since it uses as much as digits as its factorization.

1661213303 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1944, while the sum is 26.

The square root of 1661213303 is about 40757.9845306414. The cubic root of 1661213303 is about 1184.3365530255.

Adding to 1661213303 its reverse (3033121661), we get a palindrome (4694334964).

The spelling of 1661213303 in words is "one billion, six hundred sixty-one million, two hundred thirteen thousand, three hundred three".