61000004581 has 2 divisors, whose sum is σ = 61000004582. Its totient is φ = 61000004580.

The previous prime is 61000004579. The next prime is 61000004587. The reversal of 61000004581 is 18540000016.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 44599104225 + 16400900356 = 211185^2 + 128066^2 .

It is a cyclic number.

It is not a de Polignac number, because 61000004581 - 2¹ = 61000004579 is a prime.

It is a super-2 number, since 2×61000004581² (a number of 22 digits) contains 22 as substring.

Together with 61000004579, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61000004587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30500002290 + 30500002291.

It is an arithmetic number, because the mean of its divisors is an integer number (30500002291).

Almost surely, 2^61000004581 is an apocalyptic number.

It is an amenable number.

61000004581 is a deficient number, since it is larger than the sum of its proper divisors (1).

61000004581 is an equidigital number, since it uses as much as digits as its factorization.

61000004581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 960, while the sum is 25.

Adding to 61000004581 its reverse (18540000016), we get a palindrome (79540004597).

The spelling of 61000004581 in words is "sixty-one billion, four thousand, five hundred eighty-one".