217942946 has 16 divisors (see below), whose sum is σ = 364203000. Its totient is φ = 97120128.

The previous prime is 217942931. The next prime is 217942969. The reversal of 217942946 is 649249712.

It can be written as a sum of positive squares in 4 ways, for example, as 142444225 + 75498721 = 11935^2 + 8689^2 .

It is a super-2 number, since 2×217942946² = 94998255422317832, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 217942897 and 217942906.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 143771 + ... + 145278.

Almost surely, 2^217942946 is an apocalyptic number.

217942946 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

217942946 is a deficient number, since it is larger than the sum of its proper divisors (146260054).

217942946 is a wasteful number, since it uses less digits than its factorization.

217942946 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 289093.

The product of its digits is 217728, while the sum is 44.

The square root of 217942946 is about 14762.8908415662. The cubic root of 217942946 is about 601.7936567236.

The spelling of 217942946 in words is "two hundred seventeen million, nine hundred forty-two thousand, nine hundred forty-six".