78004921877 has 2 divisors, whose sum is σ = 78004921878. Its totient is φ = 78004921876.

The previous prime is 78004921873. The next prime is 78004921901. The reversal of 78004921877 is 77812940087.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 62985438961 + 15019482916 = 250969^2 + 122554^2 .

It is a cyclic number.

It is not a de Polignac number, because 78004921877 - 2² = 78004921873 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78004921873) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39002460938 + 39002460939.

It is an arithmetic number, because the mean of its divisors is an integer number (39002460939).

Almost surely, 2^78004921877 is an apocalyptic number.

It is an amenable number.

78004921877 is a deficient number, since it is larger than the sum of its proper divisors (1).

78004921877 is an equidigital number, since it uses as much as digits as its factorization.

78004921877 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1580544, while the sum is 53.

The spelling of 78004921877 in words is "seventy-eight billion, four million, nine hundred twenty-one thousand, eight hundred seventy-seven".