66949807 has 4 divisors (see below), whose sum is σ = 66976200. Its totient is φ = 66923416.

The previous prime is 66949781. The next prime is 66949811. The reversal of 66949807 is 70894966.

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

It is a 3-Lehmer number, since φ(66949807) divides (66949807-1)³.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66949807 is a prime.

It is a pancake number, because a pancake can be divided into 66949807 parts by 11571 straight cuts.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66949847) 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, 8932 + ... + 14617.

It is an arithmetic number, because the mean of its divisors is an integer number (16744050).

Almost surely, 2^66949807 is an apocalyptic number.

66949807 is a deficient number, since it is larger than the sum of its proper divisors (26393).

66949807 is a wasteful number, since it uses less digits than its factorization.

66949807 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26392.

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

The square root of 66949807 is about 8182.2861719693. The cubic root of 66949807 is about 406.0533611826.

The spelling of 66949807 in words is "sixty-six million, nine hundred forty-nine thousand, eight hundred seven".