213221615 has 8 divisors (see below), whose sum is σ = 266990688. Its totient is φ = 163160800.

The previous prime is 213221611. The next prime is 213221647. The reversal of 213221615 is 516122312.

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

It is not a de Polignac number, because 213221615 - 2² = 213221611 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213221611) 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, 926936 + ... + 927165.

It is an arithmetic number, because the mean of its divisors is an integer number (33373836).

Almost surely, 2^213221615 is an apocalyptic number.

213221615 is a deficient number, since it is larger than the sum of its proper divisors (53769073).

213221615 is a wasteful number, since it uses less digits than its factorization.

213221615 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1854129.

The product of its digits is 720, while the sum is 23.

The square root of 213221615 is about 14602.1099502777. The cubic root of 213221615 is about 597.4163115224.

Adding to 213221615 its reverse (516122312), we get a palindrome (729343927).

It can be divided in two parts, 213221 and 615, that multiplied together give a triangular number (131130915 = T₁₆₁₉₄).

The spelling of 213221615 in words is "two hundred thirteen million, two hundred twenty-one thousand, six hundred fifteen".