216401642 has 4 divisors (see below), whose sum is σ = 324602466. Its totient is φ = 108200820.

The previous prime is 216401639. The next prime is 216401657. The reversal of 216401642 is 246104612.

216401642 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 214886281 + 1515361 = 14659^2 + 1231^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 54100409 + ... + 54100412.

Almost surely, 2^216401642 is an apocalyptic number.

216401642 is a deficient number, since it is larger than the sum of its proper divisors (108200824).

216401642 is a wasteful number, since it uses less digits than its factorization.

216401642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108200823.

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 216401642 is about 14710.5962489629. The cubic root of 216401642 is about 600.3716604740.

The spelling of 216401642 in words is "two hundred sixteen million, four hundred one thousand, six hundred forty-two".