61403809 has 2 divisors, whose sum is σ = 61403810. Its totient is φ = 61403808.

The previous prime is 61403807. The next prime is 61403819. The reversal of 61403809 is 90830416.

61403809 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50013184 + 11390625 = 7072^2 + 3375^2 .

It is a cyclic number.

It is not a de Polignac number, because 61403809 - 2¹ = 61403807 is a prime.

Together with 61403807, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (61403803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30701904 + 30701905.

It is an arithmetic number, because the mean of its divisors is an integer number (30701905).

Almost surely, 2^61403809 is an apocalyptic number.

It is an amenable number.

61403809 is a deficient number, since it is larger than the sum of its proper divisors (1).

61403809 is an equidigital number, since it uses as much as digits as its factorization.

61403809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 61403809 is about 7836.0582565471. The cubic root of 61403809 is about 394.5164386533.

The spelling of 61403809 in words is "sixty-one million, four hundred three thousand, eight hundred nine".