66736691 has 8 divisors (see below), whose sum is σ = 76693344. Its totient is φ = 56885760.

The previous prime is 66736619. The next prime is 66736693. The reversal of 66736691 is 19663766.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66736691 - 2¹⁸ = 66474547 is a prime.

It is a super-4 number, since 4×66736691⁴ (a number of 32 digits) contains 4444 as substring.

It is not an unprimeable number, because it can be changed into a prime (66736693) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25070 + ... + 27603.

It is an arithmetic number, because the mean of its divisors is an integer number (9586668).

Almost surely, 2^66736691 is an apocalyptic number.

66736691 is a deficient number, since it is larger than the sum of its proper divisors (9956653).

66736691 is a wasteful number, since it uses less digits than its factorization.

66736691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52861.

The product of its digits is 244944, while the sum is 44.

The square root of 66736691 is about 8169.2527810076. The cubic root of 66736691 is about 405.6220507413.

The spelling of 66736691 in words is "sixty-six million, seven hundred thirty-six thousand, six hundred ninety-one".