66049978 has 24 divisors (see below), whose sum is σ = 103653108. Its totient is φ = 31554432.

The previous prime is 66049961. The next prime is 66049979. The reversal of 66049978 is 87994066.

It can be written as a sum of positive squares in 2 ways, for example, as 66048129 + 1849 = 8127^2 + 43^2 .

It is not an unprimeable number, because it can be changed into a prime (66049979) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 195826 + ... + 196162.

Almost surely, 2^66049978 is an apocalyptic number.

66049978 is a deficient number, since it is larger than the sum of its proper divisors (37603130).

66049978 is a wasteful number, since it uses less digits than its factorization.

66049978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 478 (or 435 counting only the distinct ones).

The product of its (nonzero) digits is 653184, while the sum is 49.

The square root of 66049978 is about 8127.1137558176. The cubic root of 66049978 is about 404.2259829381.

The spelling of 66049978 in words is "sixty-six million, forty-nine thousand, nine hundred seventy-eight".