213997021 has 8 divisors (see below), whose sum is σ = 245983104. Its totient is φ = 182364720.

The previous prime is 213997009. The next prime is 213997031. The reversal of 213997021 is 120799312.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 213997021 - 2¹³ = 213988829 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 (213997031) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 87145 + ... + 89566.

It is an arithmetic number, because the mean of its divisors is an integer number (30747888).

Almost surely, 2^213997021 is an apocalyptic number.

It is an amenable number.

213997021 is a deficient number, since it is larger than the sum of its proper divisors (31986083).

213997021 is a wasteful number, since it uses less digits than its factorization.

213997021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 176891.

The product of its (nonzero) digits is 6804, while the sum is 34.

The square root of 213997021 is about 14628.6370178496. The cubic root of 213997021 is about 598.1396274667.

The spelling of 213997021 in words is "two hundred thirteen million, nine hundred ninety-seven thousand, twenty-one".