61150781 has 2 divisors, whose sum is σ = 61150782. Its totient is φ = 61150780.

The previous prime is 61150777. The next prime is 61150787. The reversal of 61150781 is 18705116.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 30625156 + 30525625 = 5534^2 + 5525^2 .

It is a cyclic number.

It is not a de Polignac number, because 61150781 - 2² = 61150777 is a prime.

It is a super-2 number, since 2×61150781² = 7478836033819922, which contains 22 as substring.

It is a Chen prime.

It is equal to p_3626408 and since 61150781 and 3626408 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61150787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30575390 + 30575391.

It is an arithmetic number, because the mean of its divisors is an integer number (30575391).

Almost surely, 2^61150781 is an apocalyptic number.

It is an amenable number.

61150781 is a deficient number, since it is larger than the sum of its proper divisors (1).

61150781 is an equidigital number, since it uses as much as digits as its factorization.

61150781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1680, while the sum is 29.

The square root of 61150781 is about 7819.8964826908. The cubic root of 61150781 is about 393.9737951428.

Adding to 61150781 its reverse (18705116), we get a palindrome (79855897).

The spelling of 61150781 in words is "sixty-one million, one hundred fifty thousand, seven hundred eighty-one".