1991260577 has 2 divisors, whose sum is σ = 1991260578. Its totient is φ = 1991260576.

The previous prime is 1991260573. The next prime is 1991260651. The reversal of 1991260577 is 7750621991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1723578256 + 267682321 = 41516^2 + 16361^2 .

It is a cyclic number.

It is not a de Polignac number, because 1991260577 - 2² = 1991260573 is a prime.

It is not a weakly prime, because it can be changed into another prime (1991260573) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 995630288 + 995630289.

It is an arithmetic number, because the mean of its divisors is an integer number (995630289).

Almost surely, 2^1991260577 is an apocalyptic number.

It is an amenable number.

1991260577 is a deficient number, since it is larger than the sum of its proper divisors (1).

1991260577 is an equidigital number, since it uses as much as digits as its factorization.

1991260577 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 238140, while the sum is 47.

The square root of 1991260577 is about 44623.5428557617. The cubic root of 1991260577 is about 1258.0832065077.

The spelling of 1991260577 in words is "one billion, nine hundred ninety-one million, two hundred sixty thousand, five hundred seventy-seven".