1656036661 has 2 divisors, whose sum is σ = 1656036662. Its totient is φ = 1656036660.

The previous prime is 1656036653. The next prime is 1656036719. The reversal of 1656036661 is 1666306561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1353798436 + 302238225 = 36794^2 + 17385^2 .

It is a cyclic number.

It is not a de Polignac number, because 1656036661 - 2³ = 1656036653 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1656036611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 828018330 + 828018331.

It is an arithmetic number, because the mean of its divisors is an integer number (828018331).

Almost surely, 2^1656036661 is an apocalyptic number.

It is an amenable number.

1656036661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1656036661 is an equidigital number, since it uses as much as digits as its factorization.

1656036661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 116640, while the sum is 40.

The square root of 1656036661 is about 40694.4303437215. The cubic root of 1656036661 is about 1183.1050704504.

The spelling of 1656036661 in words is "one billion, six hundred fifty-six million, thirty-six thousand, six hundred sixty-one".