66798554 has 4 divisors (see below), whose sum is σ = 100197834. Its totient is φ = 33399276.

The previous prime is 66798533. The next prime is 66798569. The reversal of 66798554 is 45589766.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 45589766 = 2 ⋅22794883.

It can be written as a sum of positive squares in only one way, i.e., 66797929 + 625 = 8173^2 + 25^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16699637 + ... + 16699640.

Almost surely, 2^66798554 is an apocalyptic number.

66798554 is a deficient number, since it is larger than the sum of its proper divisors (33399280).

66798554 is a wasteful number, since it uses less digits than its factorization.

66798554 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33399279.

The product of its digits is 1814400, while the sum is 50.

The square root of 66798554 is about 8173.0382355645. The cubic root of 66798554 is about 405.7473453733.

The spelling of 66798554 in words is "sixty-six million, seven hundred ninety-eight thousand, five hundred fifty-four".