61219861 has 2 divisors, whose sum is σ = 61219862. Its totient is φ = 61219860.

The previous prime is 61219849. The next prime is 61219871. The reversal of 61219861 is 16891216.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 60933636 + 286225 = 7806^2 + 535^2 .

It is a cyclic number.

It is not a de Polignac number, because 61219861 - 2⁷ = 61219733 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61219871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30609930 + 30609931.

It is an arithmetic number, because the mean of its divisors is an integer number (30609931).

Almost surely, 2^61219861 is an apocalyptic number.

It is an amenable number.

61219861 is a deficient number, since it is larger than the sum of its proper divisors (1).

61219861 is an equidigital number, since it uses as much as digits as its factorization.

61219861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5184, while the sum is 34.

The square root of 61219861 is about 7824.3121742425. The cubic root of 61219861 is about 394.1220923382.

The spelling of 61219861 in words is "sixty-one million, two hundred nineteen thousand, eight hundred sixty-one".