61213709 has 2 divisors, whose sum is σ = 61213710. Its totient is φ = 61213708.

The previous prime is 61213699. The next prime is 61213727. The reversal of 61213709 is 90731216.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 52345225 + 8868484 = 7235^2 + 2978^2 .

It is a cyclic number.

It is not a de Polignac number, because 61213709 - 2¹⁶ = 61148173 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61213729) 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, 30606854 + 30606855.

It is an arithmetic number, because the mean of its divisors is an integer number (30606855).

Almost surely, 2^61213709 is an apocalyptic number.

It is an amenable number.

61213709 is a deficient number, since it is larger than the sum of its proper divisors (1).

61213709 is an equidigital number, since it uses as much as digits as its factorization.

61213709 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2268, while the sum is 29.

The square root of 61213709 is about 7823.9190307671. The cubic root of 61213709 is about 394.1088900849.

The spelling of 61213709 in words is "sixty-one million, two hundred thirteen thousand, seven hundred nine".