66978748 has 24 divisors (see below), whose sum is σ = 124220880. Its totient is φ = 31543680.

The previous prime is 66978739. The next prime is 66978749. The reversal of 66978748 is 84787966.

66978748 = T₄₂ + T₄₃ + ... + T₇₃₇.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66978749) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2286 + ... + 11797.

It is an arithmetic number, because the mean of its divisors is an integer number (5175870).

Almost surely, 2^66978748 is an apocalyptic number.

It is an amenable number.

66978748 is a deficient number, since it is larger than the sum of its proper divisors (57242132).

66978748 is a wasteful number, since it uses less digits than its factorization.

66978748 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14157 (or 14155 counting only the distinct ones).

The product of its digits is 4064256, while the sum is 55.

The square root of 66978748 is about 8184.0544963972. The cubic root of 66978748 is about 406.1118622097. Note that the first 3 decimals are identical.

The spelling of 66978748 in words is "sixty-six million, nine hundred seventy-eight thousand, seven hundred forty-eight".