213987021 has 12 divisors (see below), whose sum is σ = 293241312. Its totient is φ = 138799728.

The previous prime is 213986959. The next prime is 213987029. The reversal of 213987021 is 120789312.

213987021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 213987021 - 2¹³ = 213978829 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213987029) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 21945 + ... + 30158.

It is an arithmetic number, because the mean of its divisors is an integer number (24436776).

Almost surely, 2^213987021 is an apocalyptic number.

It is an amenable number.

213987021 is a deficient number, since it is larger than the sum of its proper divisors (79254291).

213987021 is an equidigital number, since it uses as much as digits as its factorization.

213987021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52180 (or 52143 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 33.

The square root of 213987021 is about 14628.2952185140. The cubic root of 213987021 is about 598.1303103752.

The spelling of 213987021 in words is "two hundred thirteen million, nine hundred eighty-seven thousand, twenty-one".