78771901 has 4 divisors (see below), whose sum is σ = 84831292. Its totient is φ = 72712512.

The previous prime is 78771883. The next prime is 78771907. The reversal of 78771901 is 10917787.

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

It can be written as a sum of positive squares in 2 ways, for example, as 10692900 + 68079001 = 3270^2 + 8251^2 .

It is a cyclic number.

It is not a de Polignac number, because 78771901 - 2¹⁹ = 78247613 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78771907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3029676 + ... + 3029701.

It is an arithmetic number, because the mean of its divisors is an integer number (21207823).

Almost surely, 2^78771901 is an apocalyptic number.

It is an amenable number.

78771901 is a deficient number, since it is larger than the sum of its proper divisors (6059391).

78771901 is a wasteful number, since it uses less digits than its factorization.

78771901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6059390.

The product of its (nonzero) digits is 24696, while the sum is 40.

The square root of 78771901 is about 8875.3535704219. The cubic root of 78771901 is about 428.6706756551.

The spelling of 78771901 in words is "seventy-eight million, seven hundred seventy-one thousand, nine hundred one".