1129411781 has 2 divisors, whose sum is σ = 1129411782. Its totient is φ = 1129411780.

The previous prime is 1129411771. The next prime is 1129411799. The reversal of 1129411781 is 1871149211.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1013849281 + 115562500 = 31841^2 + 10750^2 .

It is an emirp because it is prime and its reverse (1871149211) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1129411781 is a prime.

It is a super-2 number, since 2×1129411781² = 2551141942123183922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1129411771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 564705890 + 564705891.

It is an arithmetic number, because the mean of its divisors is an integer number (564705891).

Almost surely, 2^1129411781 is an apocalyptic number.

It is an amenable number.

1129411781 is a deficient number, since it is larger than the sum of its proper divisors (1).

1129411781 is an equidigital number, since it uses as much as digits as its factorization.

1129411781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4032, while the sum is 35.

The square root of 1129411781 is about 33606.7222590957. The cubic root of 1129411781 is about 1041.3996751404.

The spelling of 1129411781 in words is "one billion, one hundred twenty-nine million, four hundred eleven thousand, seven hundred eighty-one".