66219770 has 16 divisors (see below), whose sum is σ = 121150728. Its totient is φ = 26053440.

The previous prime is 66219761. The next prime is 66219779. The reversal of 66219770 is 7791266.

It is an interprime number because it is at equal distance from previous prime (66219761) and next prime (66219779).

It can be written as a sum of positive squares in 4 ways, for example, as 32684089 + 33535681 = 5717^2 + 5791^2 .

It is not an unprimeable number, because it can be changed into a prime (66219779) 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, 53669 + ... + 54888.

Almost surely, 2^66219770 is an apocalyptic number.

66219770 is a deficient number, since it is larger than the sum of its proper divisors (54930958).

66219770 is a wasteful number, since it uses less digits than its factorization.

66219770 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108625.

The product of its (nonzero) digits is 31752, while the sum is 38.

The square root of 66219770 is about 8137.5530720236. The cubic root of 66219770 is about 404.5720623373.

The spelling of 66219770 in words is "sixty-six million, two hundred nineteen thousand, seven hundred seventy".