1661001739 has 2 divisors, whose sum is σ = 1661001740. Its totient is φ = 1661001738.

The previous prime is 1661001599. The next prime is 1661001751. The reversal of 1661001739 is 9371001661.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1661001739 - 2⁹ = 1661001227 is a prime.

It is a super-2 number, since 2×1661001739² = 5517853553922048242, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1661001239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 830500869 + 830500870.

It is an arithmetic number, because the mean of its divisors is an integer number (830500870).

Almost surely, 2^1661001739 is an apocalyptic number.

1661001739 is a deficient number, since it is larger than the sum of its proper divisors (1).

1661001739 is an equidigital number, since it uses as much as digits as its factorization.

1661001739 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6804, while the sum is 34.

The square root of 1661001739 is about 40755.3890792371. The cubic root of 1661001739 is about 1184.2862737877.

The spelling of 1661001739 in words is "one billion, six hundred sixty-one million, one thousand, seven hundred thirty-nine".