213903997 has 4 divisors (see below), whose sum is σ = 214443196. Its totient is φ = 213364800.

The previous prime is 213903959. The next prime is 213904001. The reversal of 213903997 is 799309312.

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

It can be written as a sum of positive squares in 2 ways, for example, as 67469796 + 146434201 = 8214^2 + 12101^2 .

It is a cyclic number.

It is not a de Polignac number, because 213903997 - 2⁷ = 213903869 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213903917) 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, 269004 + ... + 269797.

It is an arithmetic number, because the mean of its divisors is an integer number (53610799).

Almost surely, 2^213903997 is an apocalyptic number.

It is an amenable number.

213903997 is a deficient number, since it is larger than the sum of its proper divisors (539199).

213903997 is an equidigital number, since it uses as much as digits as its factorization.

213903997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 539198.

The product of its (nonzero) digits is 91854, while the sum is 43.

The square root of 213903997 is about 14625.4571552482. The cubic root of 213903997 is about 598.0529449437.

The spelling of 213903997 in words is "two hundred thirteen million, nine hundred three thousand, nine hundred ninety-seven".