61618689947 has 2 divisors, whose sum is σ = 61618689948. Its totient is φ = 61618689946.

The previous prime is 61618689827. The next prime is 61618689961. The reversal of 61618689947 is 74998681616.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 61618689947 - 2¹⁶ = 61618624411 is a prime.

It is not a weakly prime, because it can be changed into another prime (61618689967) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30809344973 + 30809344974.

It is an arithmetic number, because the mean of its divisors is an integer number (30809344974).

Almost surely, 2^61618689947 is an apocalyptic number.

61618689947 is a deficient number, since it is larger than the sum of its proper divisors (1).

61618689947 is an equidigital number, since it uses as much as digits as its factorization.

61618689947 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 31352832, while the sum is 65.

The spelling of 61618689947 in words is "sixty-one billion, six hundred eighteen million, six hundred eighty-nine thousand, nine hundred forty-seven".