217649742 has 16 divisors (see below), whose sum is σ = 460905552. Its totient is φ = 68282240.

The previous prime is 217649723. The next prime is 217649777. The reversal of 217649742 is 247946712.

217649742 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 217649694 and 217649703.

It is a congruent number.

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, 1066809 + ... + 1067012.

It is an arithmetic number, because the mean of its divisors is an integer number (28806597).

Almost surely, 2^217649742 is an apocalyptic number.

217649742 is an abundant number, since it is smaller than the sum of its proper divisors (243255810).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

217649742 is a wasteful number, since it uses less digits than its factorization.

217649742 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2133843.

The product of its digits is 169344, while the sum is 42.

The square root of 217649742 is about 14752.9570595186. The cubic root of 217649742 is about 601.5236663484.

The spelling of 217649742 in words is "two hundred seventeen million, six hundred forty-nine thousand, seven hundred forty-two".