61688601605987 has 4 divisors (see below), whose sum is σ = 61703680710936. Its totient is φ = 61673522501040.

The previous prime is 61688601605977. The next prime is 61688601605993. The reversal of 61688601605987 is 78950610688616.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 61688601605987 - 2⁴ = 61688601605971 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 61688601605987.

It is not an unprimeable number, because it can be changed into a prime (61688601605977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7539546338 + ... + 7539554519.

It is an arithmetic number, because the mean of its divisors is an integer number (15425920177734).

Almost surely, 2^{61688601605987} is an apocalyptic number.

61688601605987 is a deficient number, since it is larger than the sum of its proper divisors (15079104949).

61688601605987 is a wasteful number, since it uses less digits than its factorization.

61688601605987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15079104948.

The product of its (nonzero) digits is 209018880, while the sum is 71.

The spelling of 61688601605987 in words is "sixty-one trillion, six hundred eighty-eight billion, six hundred one million, six hundred five thousand, nine hundred eighty-seven".