61403561 has 2 divisors, whose sum is σ = 61403562. Its totient is φ = 61403560.

The previous prime is 61403539. The next prime is 61403581. The reversal of 61403561 is 16530416.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 37589161 + 23814400 = 6131^2 + 4880^2 .

It is a cyclic number.

It is not a de Polignac number, because 61403561 - 2¹⁴ = 61387177 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 61403561.

It is not a weakly prime, because it can be changed into another prime (61403501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30701780 + 30701781.

It is an arithmetic number, because the mean of its divisors is an integer number (30701781).

Almost surely, 2^61403561 is an apocalyptic number.

It is an amenable number.

61403561 is a deficient number, since it is larger than the sum of its proper divisors (1).

61403561 is an equidigital number, since it uses as much as digits as its factorization.

61403561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 61403561 is about 7836.0424322486. The cubic root of 61403561 is about 394.5159075234.

Adding to 61403561 its reverse (16530416), we get a palindrome (77933977).

The spelling of 61403561 in words is "sixty-one million, four hundred three thousand, five hundred sixty-one".