78777949 has 8 divisors (see below), whose sum is σ = 86288760. Its totient is φ = 71586816.

The previous prime is 78777947. The next prime is 78777961. The reversal of 78777949 is 94977787.

It can be written as a sum of positive squares in 4 ways, for example, as 2913849 + 75864100 = 1707^2 + 8710^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 78777949 - 2¹ = 78777947 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 78777893 and 78777902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78777947) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 79404 + ... + 80389.

It is an arithmetic number, because the mean of its divisors is an integer number (10786095).

Almost surely, 2^78777949 is an apocalyptic number.

It is an amenable number.

78777949 is a deficient number, since it is larger than the sum of its proper divisors (7510811).

78777949 is a wasteful number, since it uses less digits than its factorization.

78777949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159839.

The product of its digits is 6223392, while the sum is 58.

The square root of 78777949 is about 8875.6942827026. The cubic root of 78777949 is about 428.6816462926.

The spelling of 78777949 in words is "seventy-eight million, seven hundred seventy-seven thousand, nine hundred forty-nine".