213534721 has 8 divisors (see below), whose sum is σ = 218381184. Its totient is φ = 208718640.

The previous prime is 213534703. The next prime is 213534781. The reversal of 213534721 is 127435312.

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 213534721 - 2⁷ = 213534593 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 213534721.

It is not an unprimeable number, because it can be changed into a prime (213534781) 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, 6930 + ... + 21796.

It is an arithmetic number, because the mean of its divisors is an integer number (27297648).

Almost surely, 2^213534721 is an apocalyptic number.

It is an amenable number.

213534721 is a deficient number, since it is larger than the sum of its proper divisors (4846463).

213534721 is a wasteful number, since it uses less digits than its factorization.

213534721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15191.

The product of its digits is 5040, while the sum is 28.

The square root of 213534721 is about 14612.8272760613. The cubic root of 213534721 is about 597.7085945006.

It can be divided in two parts, 2135 and 34721, that added together give a triangular number (36856 = T₂₇₁).

The spelling of 213534721 in words is "two hundred thirteen million, five hundred thirty-four thousand, seven hundred twenty-one".