221216739 has 4 divisors (see below), whose sum is σ = 294955656. Its totient is φ = 147477824.

The previous prime is 221216731. The next prime is 221216741. The reversal of 221216739 is 937612122.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 221216739 - 2³ = 221216731 is a prime.

It is a super-2 number, since 2×221216739² = 97873691227588242, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (221216731) 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, 36869454 + ... + 36869459.

It is an arithmetic number, because the mean of its divisors is an integer number (73738914).

Almost surely, 2^221216739 is an apocalyptic number.

221216739 is a deficient number, since it is larger than the sum of its proper divisors (73738917).

221216739 is an equidigital number, since it uses as much as digits as its factorization.

221216739 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73738916.

The product of its digits is 9072, while the sum is 33.

The square root of 221216739 is about 14873.3566823364. The cubic root of 221216739 is about 604.7919408421.

The spelling of 221216739 in words is "two hundred twenty-one million, two hundred sixteen thousand, seven hundred thirty-nine".