213901906 has 4 divisors (see below), whose sum is σ = 320852862. Its totient is φ = 106950952.

The previous prime is 213901903. The next prime is 213901907. The reversal of 213901906 is 609109312.

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., 201895681 + 12006225 = 14209^2 + 3465^2 .

It is a super-3 number, since 3×213901906³ (a number of 26 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (213901903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 53475475 + ... + 53475478.

Almost surely, 2^213901906 is an apocalyptic number.

213901906 is a deficient number, since it is larger than the sum of its proper divisors (106950956).

213901906 is a wasteful number, since it uses less digits than its factorization.

213901906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106950955.

The product of its (nonzero) digits is 2916, while the sum is 31.

The square root of 213901906 is about 14625.3856701285. The cubic root of 213901906 is about 598.0509961991.

The spelling of 213901906 in words is "two hundred thirteen million, nine hundred one thousand, nine hundred six".