61428581 has 2 divisors, whose sum is σ = 61428582. Its totient is φ = 61428580.

The previous prime is 61428559. The next prime is 61428589. The reversal of 61428581 is 18582416.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 58277956 + 3150625 = 7634^2 + 1775^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61428581 is a prime.

It is a super-2 number, since 2×61428581² = 7546941127347122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61428589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30714290 + 30714291.

It is an arithmetic number, because the mean of its divisors is an integer number (30714291).

Almost surely, 2^61428581 is an apocalyptic number.

It is an amenable number.

61428581 is a deficient number, since it is larger than the sum of its proper divisors (1).

61428581 is an equidigital number, since it uses as much as digits as its factorization.

61428581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15360, while the sum is 35.

The square root of 61428581 is about 7837.6387388039. The cubic root of 61428581 is about 394.5694844792.

The spelling of 61428581 in words is "sixty-one million, four hundred twenty-eight thousand, five hundred eighty-one".