1661052661 has 2 divisors, whose sum is σ = 1661052662. Its totient is φ = 1661052660.

The previous prime is 1661052649. The next prime is 1661052667. The reversal of 1661052661 is 1662501661.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1615557636 + 45495025 = 40194^2 + 6745^2 .

It is a cyclic number.

It is not a de Polignac number, because 1661052661 - 2²¹ = 1658955509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1661052667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 830526330 + 830526331.

It is an arithmetic number, because the mean of its divisors is an integer number (830526331).

Almost surely, 2^1661052661 is an apocalyptic number.

It is an amenable number.

1661052661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1661052661 is an equidigital number, since it uses as much as digits as its factorization.

1661052661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12960, while the sum is 34.

The square root of 1661052661 is about 40756.0138016465. The cubic root of 1661052661 is about 1184.2983760446.

The spelling of 1661052661 in words is "one billion, six hundred sixty-one million, fifty-two thousand, six hundred sixty-one".