1781867741 has 2 divisors, whose sum is σ = 1781867742. Its totient is φ = 1781867740.

The previous prime is 1781867723. The next prime is 1781867771. The reversal of 1781867741 is 1477681871.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1664232025 + 117635716 = 40795^2 + 10846^2 .

It is a cyclic number.

It is not a de Polignac number, because 1781867741 - 2¹⁰ = 1781866717 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1781867741.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1781867771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 890933870 + 890933871.

It is an arithmetic number, because the mean of its divisors is an integer number (890933871).

Almost surely, 2^1781867741 is an apocalyptic number.

It is an amenable number.

1781867741 is a deficient number, since it is larger than the sum of its proper divisors (1).

1781867741 is an equidigital number, since it uses as much as digits as its factorization.

1781867741 is an evil number, because the sum of its binary digits is even.

The product of its digits is 526848, while the sum is 50.

The square root of 1781867741 is about 42212.1752697015. The cubic root of 1781867741 is about 1212.3420115970.

The spelling of 1781867741 in words is "one billion, seven hundred eighty-one million, eight hundred sixty-seven thousand, seven hundred forty-one".