78820547642 has 4 divisors (see below), whose sum is σ = 118230821466. Its totient is φ = 39410273820.

The previous prime is 78820547573. The next prime is 78820547669. The reversal of 78820547642 is 24674502887.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 24674502887 = 24107 ⋅1023541.

It can be written as a sum of positive squares in only one way, i.e., 42262725241 + 36557822401 = 205579^2 + 191201^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19705136909 + ... + 19705136912.

Almost surely, 2^78820547642 is an apocalyptic number.

78820547642 is a deficient number, since it is larger than the sum of its proper divisors (39410273824).

78820547642 is a wasteful number, since it uses less digits than its factorization.

78820547642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39410273823.

The product of its (nonzero) digits is 6021120, while the sum is 53.

The spelling of 78820547642 in words is "seventy-eight billion, eight hundred twenty million, five hundred forty-seven thousand, six hundred forty-two".