66978910 has 16 divisors (see below), whose sum is σ = 124451712. Its totient is φ = 25927200.

The previous prime is 66978881. The next prime is 66978931. The reversal of 66978910 is 1987966.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 107721 + ... + 108340.

It is an arithmetic number, because the mean of its divisors is an integer number (7778232).

Almost surely, 2^66978910 is an apocalyptic number.

66978910 is a deficient number, since it is larger than the sum of its proper divisors (57472802).

66978910 is a wasteful number, since it uses less digits than its factorization.

66978910 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 216099.

The product of its (nonzero) digits is 163296, while the sum is 46.

The square root of 66978910 is about 8184.0643936861. The cubic root of 66978910 is about 406.1121896273.

The spelling of 66978910 in words is "sixty-six million, nine hundred seventy-eight thousand, nine hundred ten".