216451994 has 8 divisors (see below), whose sum is σ = 354194208. Its totient is φ = 98387260.

The previous prime is 216451993. The next prime is 216451999. The reversal of 216451994 is 499154612.

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 (216451993) 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, 4919342 + ... + 4919385.

It is an arithmetic number, because the mean of its divisors is an integer number (44274276).

Almost surely, 2^216451994 is an apocalyptic number.

216451994 is a deficient number, since it is larger than the sum of its proper divisors (137742214).

216451994 is a wasteful number, since it uses less digits than its factorization.

216451994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9838740.

The product of its digits is 77760, while the sum is 41.

The square root of 216451994 is about 14712.3075688350. The cubic root of 216451994 is about 600.4182213800.

The spelling of 216451994 in words is "two hundred sixteen million, four hundred fifty-one thousand, nine hundred ninety-four".