61856618078 has 4 divisors (see below), whose sum is σ = 92784927120. Its totient is φ = 30928309038.

The previous prime is 61856618077. The next prime is 61856618107. The reversal of 61856618078 is 87081665816.

It is a happy number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61856618077) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15464154518 + ... + 15464154521.

It is an arithmetic number, because the mean of its divisors is an integer number (23196231780).

Almost surely, 2^61856618078 is an apocalyptic number.

61856618078 is a deficient number, since it is larger than the sum of its proper divisors (30928309042).

61856618078 is a wasteful number, since it uses less digits than its factorization.

61856618078 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30928309041.

The product of its (nonzero) digits is 3870720, while the sum is 56.

The spelling of 61856618078 in words is "sixty-one billion, eight hundred fifty-six million, six hundred eighteen thousand, seventy-eight".