8451779978 has 4 divisors (see below), whose sum is σ = 12677669970. Its totient is φ = 4225889988.

The previous prime is 8451779971. The next prime is 8451779983. The reversal of 8451779978 is 8799771548.

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

It can be written as a sum of positive squares in only one way, i.e., 6829865449 + 1621914529 = 82643^2 + 40273^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (8451779971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2112944993 + ... + 2112944996.

Almost surely, 2^8451779978 is an apocalyptic number.

8451779978 is a deficient number, since it is larger than the sum of its proper divisors (4225889992).

8451779978 is a wasteful number, since it uses less digits than its factorization.

8451779978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4225889991.

The product of its digits is 35562240, while the sum is 65.

The square root of 8451779978 is about 91933.5628483961. The cubic root of 8451779978 is about 2036.9610636168.

The spelling of 8451779978 in words is "eight billion, four hundred fifty-one million, seven hundred seventy-nine thousand, nine hundred seventy-eight".