213007921 has 4 divisors (see below), whose sum is σ = 243437632. Its totient is φ = 182578212.

The previous prime is 213007891. The next prime is 213007933. The reversal of 213007921 is 129700312.

213007921 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, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 213007921 - 2²¹ = 210910769 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (213007961) 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, 15214845 + ... + 15214858.

It is an arithmetic number, because the mean of its divisors is an integer number (60859408).

Almost surely, 2^213007921 is an apocalyptic number.

It is an amenable number.

213007921 is a deficient number, since it is larger than the sum of its proper divisors (30429711).

213007921 is an equidigital number, since it uses as much as digits as its factorization.

213007921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30429710.

The product of its (nonzero) digits is 756, while the sum is 25.

The square root of 213007921 is about 14594.7908857921. The cubic root of 213007921 is about 597.2166648558.

The spelling of 213007921 in words is "two hundred thirteen million, seven thousand, nine hundred twenty-one".