213402421 has 16 divisors (see below), whose sum is σ = 226442304. Its totient is φ = 200841984.

The previous prime is 213402373. The next prime is 213402457. The reversal of 213402421 is 124204312.

It is a cyclic number.

It is not a de Polignac number, because 213402421 - 2¹⁷ = 213271349 is a prime.

It is a super-2 number, since 2×213402421² = 91081186577322482, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213402521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 179190 + ... + 180376.

It is an arithmetic number, because the mean of its divisors is an integer number (14152644).

Almost surely, 2^213402421 is an apocalyptic number.

It is an amenable number.

213402421 is a deficient number, since it is larger than the sum of its proper divisors (13039883).

213402421 is a wasteful number, since it uses less digits than its factorization.

213402421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1380.

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 213402421 is about 14608.2997299480. The cubic root of 213402421 is about 597.5851279537.

Adding to 213402421 its reverse (124204312), we get a palindrome (337606733).

The spelling of 213402421 in words is "two hundred thirteen million, four hundred two thousand, four hundred twenty-one".