66788770 has 8 divisors (see below), whose sum is σ = 120219804. Its totient is φ = 26715504.

The previous prime is 66788753. The next prime is 66788783. The reversal of 66788770 is 7788766.

It can be written as a sum of positive squares in 2 ways, for example, as 65173329 + 1615441 = 8073^2 + 1271^2 .

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

It is a super-2 number, since 2×66788770² = 8921479596225800, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3339429 + ... + 3339448.

Almost surely, 2^66788770 is an apocalyptic number.

66788770 is a deficient number, since it is larger than the sum of its proper divisors (53431034).

66788770 is a wasteful number, since it uses less digits than its factorization.

66788770 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6678884.

The product of its (nonzero) digits is 790272, while the sum is 49.

The square root of 66788770 is about 8172.4396602239. The cubic root of 66788770 is about 405.7275344362.

The spelling of 66788770 in words is "sixty-six million, seven hundred eighty-eight thousand, seven hundred seventy".