66764402 has 4 divisors (see below), whose sum is σ = 100146606. Its totient is φ = 33382200.

The previous prime is 66764387. The next prime is 66764449. The reversal of 66764402 is 20446766.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 20446766 = 2 ⋅10223383.

It can be written as a sum of positive squares in only one way, i.e., 58232161 + 8532241 = 7631^2 + 2921^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16691099 + ... + 16691102.

Almost surely, 2^66764402 is an apocalyptic number.

66764402 is a deficient number, since it is larger than the sum of its proper divisors (33382204).

66764402 is a wasteful number, since it uses less digits than its factorization.

66764402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33382203.

The product of its (nonzero) digits is 48384, while the sum is 35.

The square root of 66764402 is about 8170.9486597335. The cubic root of 66764402 is about 405.6781849662.

The spelling of 66764402 in words is "sixty-six million, seven hundred sixty-four thousand, four hundred two".