61261813 has 2 divisors, whose sum is σ = 61261814. Its totient is φ = 61261812.

The previous prime is 61261807. The next prime is 61261841. The reversal of 61261813 is 31816216.

It is an a-pointer prime, because the next prime (61261841) can be obtained adding 61261813 to its sum of digits (28).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 32285124 + 28976689 = 5682^2 + 5383^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61261813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61261513) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30630906 + 30630907.

It is an arithmetic number, because the mean of its divisors is an integer number (30630907).

Almost surely, 2^61261813 is an apocalyptic number.

It is an amenable number.

61261813 is a deficient number, since it is larger than the sum of its proper divisors (1).

61261813 is an equidigital number, since it uses as much as digits as its factorization.

61261813 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1728, while the sum is 28.

The square root of 61261813 is about 7826.9925897499. The cubic root of 61261813 is about 394.2120981762.

The spelling of 61261813 in words is "sixty-one million, two hundred sixty-one thousand, eight hundred thirteen".