6657949978 has 64 divisors (see below), whose sum is σ = 11332949760. Its totient is φ = 2920845312.

The previous prime is 6657949939. The next prime is 6657950009. The reversal of 6657949978 is 8799497566.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 2120826 + ... + 2123962.

It is an arithmetic number, because the mean of its divisors is an integer number (177077340).

Almost surely, 2^6657949978 is an apocalyptic number.

6657949978 is a deficient number, since it is larger than the sum of its proper divisors (4674999782).

6657949978 is a wasteful number, since it uses less digits than its factorization.

6657949978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3271.

The product of its digits is 205752960, while the sum is 70.

The square root of 6657949978 is about 81596.2620344829. The cubic root of 6657949978 is about 1881.2514281907.

The spelling of 6657949978 in words is "six billion, six hundred fifty-seven million, nine hundred forty-nine thousand, nine hundred seventy-eight".