1200787661 has 2 divisors, whose sum is σ = 1200787662. Its totient is φ = 1200787660.

The previous prime is 1200787633. The next prime is 1200787723. The reversal of 1200787661 is 1667870021.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 992880100 + 207907561 = 31510^2 + 14419^2 .

It is a cyclic number.

It is not a de Polignac number, because 1200787661 - 2¹⁴ = 1200771277 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1200787261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 600393830 + 600393831.

It is an arithmetic number, because the mean of its divisors is an integer number (600393831).

Almost surely, 2^1200787661 is an apocalyptic number.

It is an amenable number.

1200787661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1200787661 is an equidigital number, since it uses as much as digits as its factorization.

1200787661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 28224, while the sum is 38.

The square root of 1200787661 is about 34652.3831936564. The cubic root of 1200787661 is about 1062.8910224169.

The spelling of 1200787661 in words is "one billion, two hundred million, seven hundred eighty-seven thousand, six hundred sixty-one".