61639663 has 2 divisors, whose sum is σ = 61639664. Its totient is φ = 61639662.

The previous prime is 61639657. The next prime is 61639673. The reversal of 61639663 is 36693616.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61639663 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61639673) 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, 30819831 + 30819832.

It is an arithmetic number, because the mean of its divisors is an integer number (30819832).

Almost surely, 2^61639663 is an apocalyptic number.

61639663 is a deficient number, since it is larger than the sum of its proper divisors (1).

61639663 is an equidigital number, since it uses as much as digits as its factorization.

61639663 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 104976, while the sum is 40.

The square root of 61639663 is about 7851.0931086060. The cubic root of 61639663 is about 395.0209100718.

The spelling of 61639663 in words is "sixty-one million, six hundred thirty-nine thousand, six hundred sixty-three".