5611209781 has 2 divisors, whose sum is σ = 5611209782. Its totient is φ = 5611209780.

The previous prime is 5611209767. The next prime is 5611209811. The reversal of 5611209781 is 1879021165.

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., 2869744900 + 2741464881 = 53570^2 + 52359^2 .

It is a cyclic number.

It is not a de Polignac number, because 5611209781 - 2⁵ = 5611209749 is a prime.

It is a super-2 number, since 2×5611209781² = 62971350412780135922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (5611209701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2805604890 + 2805604891.

It is an arithmetic number, because the mean of its divisors is an integer number (2805604891).

Almost surely, 2^5611209781 is an apocalyptic number.

It is an amenable number.

5611209781 is a deficient number, since it is larger than the sum of its proper divisors (1).

5611209781 is an equidigital number, since it uses as much as digits as its factorization.

5611209781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 30240, while the sum is 40.

The square root of 5611209781 is about 74908.0087907828. The cubic root of 5611209781 is about 1776.9921196181.

The spelling of 5611209781 in words is "five billion, six hundred eleven million, two hundred nine thousand, seven hundred eighty-one".