1331609749 has 2 divisors, whose sum is σ = 1331609750. Its totient is φ = 1331609748.

The previous prime is 1331609731. The next prime is 1331609759. The reversal of 1331609749 is 9479061331.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1168409124 + 163200625 = 34182^2 + 12775^2 .

It is a cyclic number.

It is not a de Polignac number, because 1331609749 - 2¹⁷ = 1331478677 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1331609759) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 665804874 + 665804875.

It is an arithmetic number, because the mean of its divisors is an integer number (665804875).

Almost surely, 2^1331609749 is an apocalyptic number.

It is an amenable number.

1331609749 is a deficient number, since it is larger than the sum of its proper divisors (1).

1331609749 is an equidigital number, since it uses as much as digits as its factorization.

1331609749 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 122472, while the sum is 43.

The square root of 1331609749 is about 36491.2283843666. The cubic root of 1331609749 is about 1100.1679492871.

The spelling of 1331609749 in words is "one billion, three hundred thirty-one million, six hundred nine thousand, seven hundred forty-nine".