61405999 has 2 divisors, whose sum is σ = 61406000. Its totient is φ = 61405998.

The previous prime is 61405991. The next prime is 61406039. The reversal of 61405999 is 99950416.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 61405999 - 2³ = 61405991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61405991) 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, 30702999 + 30703000.

It is an arithmetic number, because the mean of its divisors is an integer number (30703000).

Almost surely, 2^61405999 is an apocalyptic number.

61405999 is a deficient number, since it is larger than the sum of its proper divisors (1).

61405999 is an equidigital number, since it uses as much as digits as its factorization.

61405999 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 87480, while the sum is 43.

The square root of 61405999 is about 7836.1979939254. The cubic root of 61405999 is about 394.5211288115.

The spelling of 61405999 in words is "sixty-one million, four hundred five thousand, nine hundred ninety-nine".