66971402 has 4 divisors (see below), whose sum is σ = 100457106. Its totient is φ = 33485700.

The previous prime is 66971393. The next prime is 66971413. The reversal of 66971402 is 20417966.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 20417966 = 2 ⋅10208983.

It can be written as a sum of positive squares in only one way, i.e., 45171841 + 21799561 = 6721^2 + 4669^2 .

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, 16742849 + ... + 16742852.

Almost surely, 2^66971402 is an apocalyptic number.

66971402 is a deficient number, since it is larger than the sum of its proper divisors (33485704).

66971402 is a wasteful number, since it uses less digits than its factorization.

66971402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33485703.

The product of its (nonzero) digits is 18144, while the sum is 35.

The square root of 66971402 is about 8183.6056845378. The cubic root of 66971402 is about 406.0970146802.

The spelling of 66971402 in words is "sixty-six million, nine hundred seventy-one thousand, four hundred two".