221702513 has 4 divisors (see below), whose sum is σ = 222024048. Its totient is φ = 221380980.

The previous prime is 221702473. The next prime is 221702561. The reversal of 221702513 is 315207122.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 315207122 = 2 ⋅157603561.

It is a cyclic number.

It is not a de Polignac number, because 221702513 - 2¹⁰ = 221701489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221702563) 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, 159731 + ... + 161112.

It is an arithmetic number, because the mean of its divisors is an integer number (55506012).

Almost surely, 2^221702513 is an apocalyptic number.

It is an amenable number.

221702513 is a deficient number, since it is larger than the sum of its proper divisors (321535).

221702513 is an equidigital number, since it uses as much as digits as its factorization.

221702513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 321534.

The product of its (nonzero) digits is 840, while the sum is 23.

The square root of 221702513 is about 14889.6780690517. The cubic root of 221702513 is about 605.2343085333.

Adding to 221702513 its reverse (315207122), we get a palindrome (536909635).

The spelling of 221702513 in words is "two hundred twenty-one million, seven hundred two thousand, five hundred thirteen".