66791057 has 4 divisors (see below), whose sum is σ = 69695040. Its totient is φ = 63887076.

The previous prime is 66791047. The next prime is 66791059. The reversal of 66791057 is 75019766.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 66791057 - 2⁶ = 66790993 is a prime.

It is a super-2 number, since 2×66791057² = 8922090590354498, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66791059) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1451957 + ... + 1452002.

It is an arithmetic number, because the mean of its divisors is an integer number (17423760).

Almost surely, 2^66791057 is an apocalyptic number.

It is an amenable number.

66791057 is a deficient number, since it is larger than the sum of its proper divisors (2903983).

66791057 is a wasteful number, since it uses less digits than its factorization.

66791057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2903982.

The product of its (nonzero) digits is 79380, while the sum is 41.

The square root of 66791057 is about 8172.5795805241. The cubic root of 66791057 is about 405.7321653958.

The spelling of 66791057 in words is "sixty-six million, seven hundred ninety-one thousand, fifty-seven".