66691054 has 4 divisors (see below), whose sum is σ = 100036584. Its totient is φ = 33345526.

The previous prime is 66691043. The next prime is 66691061. The reversal of 66691054 is 45019666.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16672762 + ... + 16672765.

It is an arithmetic number, because the mean of its divisors is an integer number (25009146).

Almost surely, 2^66691054 is an apocalyptic number.

66691054 is a deficient number, since it is larger than the sum of its proper divisors (33345530).

66691054 is a wasteful number, since it uses less digits than its factorization.

66691054 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33345529.

The product of its (nonzero) digits is 38880, while the sum is 37.

The square root of 66691054 is about 8166.4590857972. The cubic root of 66691054 is about 405.5295699064.

The spelling of 66691054 in words is "sixty-six million, six hundred ninety-one thousand, fifty-four".