218191970 has 8 divisors (see below), whose sum is σ = 392745564. Its totient is φ = 87276784.

The previous prime is 218191951. The next prime is 218191979. The reversal of 218191970 is 79191812.

It can be written as a sum of positive squares in 2 ways, for example, as 210279001 + 7912969 = 14501^2 + 2813^2 .

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

It is not an unprimeable number, because it can be changed into a prime (218191979) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10909589 + ... + 10909608.

Almost surely, 2^218191970 is an apocalyptic number.

218191970 is a deficient number, since it is larger than the sum of its proper divisors (174553594).

218191970 is a wasteful number, since it uses less digits than its factorization.

218191970 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21819204.

The product of its (nonzero) digits is 9072, while the sum is 38.

The square root of 218191970 is about 14771.3225541926. The cubic root of 218191970 is about 602.0227748252.

The spelling of 218191970 in words is "two hundred eighteen million, one hundred ninety-one thousand, nine hundred seventy".