61102781 has 2 divisors, whose sum is σ = 61102782. Its totient is φ = 61102780.

The previous prime is 61102771. The next prime is 61102807. The reversal of 61102781 is 18720116.

It is an a-pointer prime, because the next prime (61102807) can be obtained adding 61102781 to its sum of digits (26).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 53071225 + 8031556 = 7285^2 + 2834^2 .

It is a cyclic number.

It is not a de Polignac number, because 61102781 - 2¹⁴ = 61086397 is a prime.

It is a super-2 number, since 2×61102781² = 7467099691867922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 61102781.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61102711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30551390 + 30551391.

It is an arithmetic number, because the mean of its divisors is an integer number (30551391).

Almost surely, 2^61102781 is an apocalyptic number.

It is an amenable number.

61102781 is a deficient number, since it is larger than the sum of its proper divisors (1).

61102781 is an equidigital number, since it uses as much as digits as its factorization.

61102781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 672, while the sum is 26.

The square root of 61102781 is about 7816.8267858511. The cubic root of 61102781 is about 393.8706855723.

Adding to 61102781 its reverse (18720116), we get a palindrome (79822897).

The spelling of 61102781 in words is "sixty-one million, one hundred two thousand, seven hundred eighty-one".